Journal of Pure and Applied Ultrasonics · 2015-04-28 · Journal of Pure and Applied Ultrasonics Prediction of ultrasonic velocity of benzene and acyl derivatives though QSPR analysis

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VOLUME 37 NUMBER 1 JANUARY-MARCH 2015

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Journal of Pure and Applied Ultrasonics

Prediction of ultrasonic velocity of benzene and acyl derivatives though QSPR analysis 1Neetu Sharma, Amrita Dwivedi, J.D. Pandey and A.K. Srivastava

Ultrasonic testing of graphite plates 7U. Urban Kumar, V. Rama Krishna, K. Balakrishana and P.V.S. Ganesh Kumar

Comparative study of ultrasonic absorption and relaxation behavior of polar solute and non-polar solvent 11N.R. Pawar and O.P. Chimankar

Current research in ultrasonic non-destructive evaluation of materials properties 15P. Palanichamy, M. Vasudevan and A. Joseph

D.Phil. Thesis Summary : Synthesis and ultrasonic characterization of nanoparticlesbased advanced materials and their applications 28Dr. Meher Wan

Conference report : International Symposium on Ultrasonics (ISU-2015) 29(Focal theme : Ultrasound in biomedical and industrial applications)Dr. Omprakash P. ChimankarDr. Yudhisther Kumar Yadav

(Authors have stated that the papers have not been published elsewhere)

ISSN 0256−4637

VOLUME 37 JANUARY−MARCH 2015NUMBER 1

CONTENTS

Website : www.ultrasonicsindia.org

A Publication of — Ultrasonics Society of India

1NEETU SHARMA et al., PREDICTION OF ULTRASONIC VELOCITY OF BENZENE

Prediction of ultrasonic velocity of benzene andacyl derivatives through QSPR analysis

Neetu Sharma, Amrita Dwivedi, J.D. Pandey* and A.K. Srivastava*

QSAR Laboratory, Department of Chemistry,University of Allahabad, Allahabad-211002, India

*E-mail : [email protected]; [email protected]

Quantitative structure properties relationship (QSPR) study has been performed on the series of benzene andacyl compounds. In the present work we are concerned about the modeling of ultrasonic velocity. For this purposewe have performed regression analysis and several significant models were proposed. The QSPR models suggestthat physicochemical parameter such as D, IOR, St show best result towards ultrasonic velocity of benzene derivativesand topological parameters such as 0χ, 1χ, 2χ have been found more prominent for modeling of ultrasonic velocityof acyl derivatives .The predictive ability of QSPR models were cross validated by evaluating of the residualactivity, appreciable cross validated R2 values (R2

cv) by leave one out (LOO) technique.

Keywords: Ultrasonic velocity; QSPR; regression analysis.

IntroductionUltrasonic propagation parameters (velocity, density,

absorption, relaxation etc) are used extensively to studythe physicochemical and molecular interactions in liquidsystem. Ultrasonic velocity measurements areconsiderably importance in understanding the nature ofmolecular interaction and can be used to providequalitative information about the physical nature andstrength of molecular interaction in liquids and solutions.Recent studies have also been found to use ultrasonicenergy in engineering, agriculture and medicine1-5.

Ultrasonic velocity and density data in conjugationwith equation of state can be used to estimate a numberof important and useful thermodynamic properties whichcannot be determined directly and can be obtained fromultrasonic measurements. One such property is theisentropic (adiabatic) compressibility. Ultrasonic velocityhas also been correlated with other equilibrium andtransport properties of liquid system. Now-a-daysultrasonic velocity is used as a tool to investigate variousaspects of liquids, solution, polymer, electrolyticsolutions etc.6-8.

In the present work we study the factor which affectsthe ultrasonic velocity of benzene and acyl derivativeswith the help of computational chemistry and to

developed QSPR models by applying Hansch analysis9.For this purpose we have taken the ultrasonic velocity at25°C for both the series of compound from literature10.

Descriptors and SoftwareTwo dimensional (2D) structures of all compound of

both series were drawn by using ACD Lab Chem Sketchversion 12 software (www.acdlabs.com/acdlabs-rss-feed.xml)11, physicochemical and hydrophobicparameter such as molecular weight (Mw), molecularvolume (Mv), molar refractivity (Mr), parachor (Pc),Index of refraction (IOR), surface tension (st), density(D), polarizability (Pz) and partition coefficient (LogP)were calculated with the help of this software.Topological parameters such as balaban indices (J),wiener index (W), mean wiener index (Wa), Balabancentric index (BAC) and molecular connectivity (χ) werecalculated by using E-Dragon software12, 13. The mostcommon molecular file formats that are accepted inE-Dragon software are SMILES notations, which arecreated on line by Babel software and 2D structure ofvarious derivative are converted into 3D optimizedstructures on-line using CORINA, provided by MolecularNetworks GMBH. Regression analysis was performedto develop QSPR model by using SPSS 7.5 version

J. Pure Appl. Ultrason. 37 (2015) pp. 1-6

2 J. PURE APPL. ULTRASON., VOL. 37, NO. 1 (2015)

program. The statistical significance of the models wasdetermined by examining the regression coefficient, thestandard deviation, the number of variables, the crossvalidation leave-one out statistics.

Parameter Used

Surface tension (St)

The cohesive forces between liquid molecules areresponsible for the phenomenon called surface tension.It arises from unbalanced molecular cohesive forces ator near the surface, as a result of which the surface tendsto contract and has properties resembling those of astretched elastic membrane. A surface film is thus formed,which makes it more difficult to move an object throughthe surface than to move it when it is completelysubmerged.

Partition coefficient (Log P)

The octanol-water partition coefficient, P, is a measureof the differential solubility of a neutral substancebetween the immiscible liquids and thereby, a descriptorof hydrophobicity (or the lipophilicity) of a neutralsubstance. It is typically used in its logarithmic form,log P.

Molecular connectivity indexIn first order connectivity index χ = χ(G) of a graph G

is defined by Randic14 as follows:1χ = 1χ(G) = Σij [δi

v δjv]–0.5

where δi and δj are the valence of a vertex j, equal to thenumber of bonds connected to the atoms i and j, in G1.In the case of hetero-systems the connectivity given interms of valence delta values δi

v and δjv of atoms i and j

and is denoted by 1χv. This version of the connectivityindex is called the valence connectivity index and isdefined as follows:

1χv = 1χv(G) = Σij [δiv δj

v]–0.5

where the sum is taken all bonds I-j of the molecule.Valence delta values are given by the followingexpression:

Ziv – Hi

δiv =

Zi – Zi –1

where Zi is the atomic number of atom i, Ziv is the number

of valence electron of the atom i and Hi is the number ofhydrogen atom attached to atom i.

Density (ρ)Density is a steric parameter and calculated by ACD

Lab Chem Sketch Software. This parameter is relatedwith the bulk and size of the substituent

MW (Molecular weight)ρ =

Mv (Molecular volume)

Index of refraction (IOR)The index of refraction (IOR) of a medium is the ratio

of the speed of light in vacuum to its velocity in themedium. By definition, the refractive index of a vacuumis 1, for air the value is 1.008.

Results and DiscussionQSPR studies were performed on the compounds listed

in Tables 1-2. Several physico-chemical and topologicalparameters were calculated for the both series ofcompound. The excellent results are obtained using D,IOR, St, Log P for QSPR based modeling of ultrasonicvelocity of benzene derivatives, however 0χ, 1χ, 2χ havebeen found more significant for modeling of ultrasonicvelocity of acyl derivatives. All compounds of the bothseries along with, calculated physicochemical parametersand observed ultrasonic velocity (v) are given in Table 1& 2. Linear regression analysis resulted in severalsignificant QSPR models. The significant modelsobtained in the present study are as below15-19.

Table 1 – Empirical Parameters and Ultrasonic Velocity (V) of Benzene Derivatives.

S. No. Structures Ior St D log p V(m/s)

1 Aniline 1.579 41.700 1.015 .940 16372 Cinamaldehyde 1.577 38.900 1.034 2.120 15543 o-cresrol 1.595 38.800 1.038 1.940 15064 O-cersylethylether 1.493 29.200 .941 2.590 13155 Cumene 1.491 28.400 .861 3.560 13046 Ethyl benzene 1.497 29.000 .868 3.210 13287 m-Toluidine 1.567 39.500 .992 1.400 1526


Significant models for the series of benzene derivatives

v = 1551.850 (±1020.963) D – 43.348

n = 7, R=0.868, R2=0. 753, R2A=0. 704, S.E=73.359,

F(2,7) = 15.266, Q=0.012 (1)

v = –130.966 (±67.103) logP +1747.717

n = 7, R=0.913, R2=0. 834, R2A=0. 801, S.E=60.125,

F(2,7) = 25.170, Q=0.015 (2)

v = 2678.919 (±1248.734) IOR – 2679.949

n = 7, R=0.927, R2=0. 859, R2A=0. 831, S.E=55.498,

F(2,7) = 30.411, Q=0.017 (3)

v = 22.555(±4.558) St + 661.811

n = 7, R=0.985, R2=0. 970, R2A=0. 964, S.E=25.573,

F(2,7) = 161.773, Q= 0.039 (4)

n = total no. of compounds,

R = Correlation coefficient

R2 = Coefficient of determination

RA2 = Adjusted coefficient of determination

S.E. = Standard error of estimate

F = Variance ratio20, 21

Q = Quality of fit22, 23

Equations obtained in the present analysis (1 to 4)show that the coefficient of D, IOR, St, are positive showthat the increase in the value of these parameter enhancesthe ultrasonic velocity of benzene derivatives. Negativecoefficient of Log P indicates that decrease in the valueof this parameter increases ultrasonic velocity of presentseries of compounds.

Significant models for the series of acyl derivatives

v = 20.183 (±14.627) 0χ + 1158.425

n = 7, R=0.846, R2=0. 716, R2A=0. 659, S.E=90.598,

F(2,7) = 12.581, Q=0.009 (5)

v = 28.083 (±19.911) 1χ + 1181.706

n = 7, R=0.851, R2=0. 724, R2A=0. 669, S.E=89.182,

F(2,7) = 13.144, Q=0.010 (6)

v = 37.165 (±21.098) 2χ +1166.353

n = 7, R=0.897, R2=0. 804, R2A=0. 765, S.E=75.221,

F(2,7) = 20.504, Q=0.012 (7)

In the above Eq. (5 to 7) positive coefficient ofmolecular connectivity (χ0, χ1, χ2) indicate that increasein value of these parameters enhances the ultrasonicvelocity of acyl derivatives.

Out of several QSPR model, Eq. (4) & (7) are bestmodel which show that the best descriptor for theultrasonic velocity is found to be St & 2χ for the seriesof benzene and acyl derivatives respectively. In order toconfirm that the model with excellent statistics has alsoexcellent prediction power too, we have evaluated qualityfactor Q. The predictive power as determined by thePogliani Q parameter for the model expressed by Eq.(4) [Q = 0.039] and Eq. (7) [Q = 0.012] confirms thatthis model has excellent statistics as well as excellentpredictive power.

Predicted and residual activity values for Eq. (4 & 7)are given in Table 3 & 4 respectively. Predicted valuesare the calculated activities obtained from Eq. (4 & 7)

Table 2 – Empirical Parameters and Ultrasonic Velocity (V) of Acyl Derivatives

S. No. Structures log p 0χ 1χ 2χ V(m/s)

1 Acetaldehyde –.160 3.577 1.732 1.732 16142 acetone –.160 3.577 1.732 1.732 11743 Acetonyl acetone –.270 6.569 3.626 3.365 13994 Butyl oleacte 9.750 17.719 11.808 8.339 14045 Diacetyl –1.330 5.155 2.643 2.488 12206 Diethyl ketone .910 4.992 2.808 2.808 12307 Di-n-propyl ketone –.190 2.707 1.414 .707 1246

Table 3 –Comparison between Observed V (m/s) and PredictedV(m/s) and their Residual values for Equation 4

S. Observed Predicted ResidualNo. V(m/s) V(m/s) V(m/s)

1 1637 1602.367 34.6332 1554 1539.212 14.7883 1506 1536.956 –30.9564 1315 1320.425 –5.4255 1304 1302.381 1.6196 1328 1315.914 12.0867 1526 1552.745 –26.745


added. R2A will decrease if the added variable does not

reduce the unexplained variable enough to offset the lossof decrease of freedom.

Predictive error of coefficient of correlation (PE)The predictive error of coefficient of correlation (PE)

25 is yet another parameter used to decide the predictivepower of the proposed models. We have calculated PEvalue of all the proposed models and they are reportedin Table 5.

It is argued that if the values R < PE, then suchcorrelation is not significant; however if values are R >PE in several times (at least three times), then values arecorrelated. However, if values are R > 6PE, thenmathematically the correlation is unquestionably good.For all the models developed the condition R > 6PE issatisfied and hence they can be said to have a goodpredictive power.

ConclusionThe current study was performed to examine the factor

which affects the ultrasonic velocity of benzene and acylderivatives through QSPR analysis. From the above resultand discussion, it may be concluded that physico-chemical parameter such as surface tension was foundto be more prominent towards the ultrasonic velocity ofbenzene derivatives and increase in value of thisparameter enhances the ultrasonic velocity of benzenederivatives. In the case of acyl derivative molecularconnectivity was found to be more prominent andincrease in value of this parameter enhances theultrasonic velocity of acyl derivatives.

AcknowledgmentsOne of the authors (AD) is greatful to UGC, New Delhi,

for the award of Junior Research Fellowship.

Table 5 – Predictive error of coefficient of correlation (PE) and Cross-Validation parameters for the proposed models.

Model No. N PRESS SSY PRESS/SSY R2cv

PSE R 1-R2 PE 6PE

1 7 26908.142 82156.715 0.328 0.672 62.000 0.868 0.247 0.024 0.1442 7 15399.914 93664.943 0.164 0.836 49.903 0.927 0.141 0.013 0.0783 7 18075.249 90989.608 0.199 0.831 50.815 0.913 0.166 0.016 0.0984 7 3269.864 105795.000 0.031 0.969 21.613 0.985 0.030 0.003 0.0185 7 41040.327 103269.1 0.397 0.603 76.569 0.846 0.284 0.027 0.1626 7 39766.907 104542.5 0.380 0.620 75.372 0.851 0.276 0.026 0.1567 7 28291.072 116018.4 0.244 0.756 63.573 0.897 0.103 0.010 0.060

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7 Marcus Y., Internal Pressure of Liquids andSolutions, Chemical Review, 113 (2013) 10.

8 Dey R., Saini A, Sharma A.K. and Pandey J.D.,Estimation of some important thermodynamic andthermophysical and properties of ternary liquidmixtures from ultrasonic velocity and density data,J. Mol. Liq., 195 (2014) 150-156.

9 Hansch C., Hoekaman D. and Gao H., ComparativeQSAR: toward a deeper understanding ofchemicobiological interaction, Chem. Rev. 96 (1996)1045-1075.


10 Pandey J.D., Kumar A., Ultrasonic velocity inpure liquids, J. Pure Appl. Ultrason., 16 (1994) 63-68.

11 ACD Lab Chem. Sketch version 12.0 Software(2009) Acd-Lab software for calculating the referredphysicochemical parameters. Advanced chemistrydevelopment inc. /Chemsketch ver. 12.0.www.acdlabs.com/acdlabs-rss-feed.xml. Accessed 30 Aug2013.

12 E-Dragon Software for calculation of topologicalindices: www.vcclab.org/

13 Tetko I.V., Gasteiger J., Todeschini R., Mauri A.,Livingstone D., Ertl P., Palyulin V.A., RadchenkoE.V., Zefirov N.S., Makarenko A.S., Tanchuk V.Y.and Prokopenko V.V., Virtual computationalchemistry laboratory design and description, J.Comput. Aid. Mol. Des. 19 (2005) 453-463.

14 Randic M., Characterization of molecular branching,J. Am Chem. Soc. 97 (1975) 6609.

15 Srivastava A.K., Pathak V.K., Archana, Jaiswal M.and Agarwal V.K., QSAR analysis of Mur Binhibitors with antibacterial properties discussingrole of physico-chemical parameters, Med. Chem.Res. 20 (2011) 1713-1723.

16 Srivastava A.K. and Shukla N., QSAR basedmodeling on a series of lactam fused chromanderivatives as selective 5-HT transporters. J. Saudi.Chem. Soc. 16 (2012) 405-412.

17 Dwivedi A., Srivastava A. K. and Singh A.,Molecular modeling of pyridine derivatives forCOX-2 inhibitors quantitative structure-activity

relationship study, Med. Chem. Res., 23 (2014) 1865-1877.

18 Dwivedi A., Srivastava A.K. and Singh A., In silicomolecular modeling and prediction of activity ofsubstituted tetrahydropyrans as COX-2 inhibitor,Med. Chem. Res., (2014) 1-11.

19 Dwivedi A., Srivastava A.K., Singh A, Quantitativestructure-activity relationship based modeling ofsubstituted indole Schiff bases as inhibitor of COX-2. J. Saudi. Chem. Soc. 2013 dx.doi.org/10.1016/j.jscs.2013.01.007

20 Bikash D., Shovanlal G., Subrata B., Soma S. andTarun J., QSAR study on some pyridoacridineascididiamine analogues as antitumor agents, Bioorg.Med. Chem., 11 (2003) 5493-5499.

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22 Pogliani L., Structural property relationships ofamine acids and some Peptides, Amino Acids, 6(1994) 141-156.

23 Pogliani L., Modeling with special descriptorsderived from a medium size set of connectivityindices. J. Phys. Chem., 100 (1996) 18065-18077.

24 Cramer III R.D., Bunce J.D., Patterson D.E. andFrank I.E., Cross validation, Bootstrapping, andpartial least squares compared with multipleregression in conventional QSAR studies, Quant.Struct. Act. Relat., 7 (1988) 18-25.

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7V. RAMA KRISHNA et al., ULTRA SONIC TESTING OF GRAPHITE PLATES

Ultrasonic testing of graphite plates

U. Urban Kumar, V. Rama Krishna*, K. Balakrishana and P.V.S. Ganesh Kumar

Naval Science and Technological Laboratory, Visakhapatnam; India,*E-mail : [email protected]; [email protected]

Ultrasonic testing is one of the quite frequently used non destructive evaluation methods for detecting flaws inmetals. However, the technique is not used regularly for non metals such as plastic. A need was felt for Ultrasonictesting of graphite plates in one of the critical applications. As no literature is found on such testing of graphiteplate, the process had to be established as ab intio. This Ultrasonic testing was to be carried out before and aftermandatory environmental tests of these plates. Significant changes, if any, are observed with respect to ultrasonicsignal amplitudes, before and after environmental tests. If any failure occurs during any of the above testing, thegraphite plate is liable to be rejected. For this test a probe is used to scan the entire area of the graphite plate.Ultrasonic probe is made out of Piezo-electric crystal having a frequency of 0.5 MHz. It is built with both transmitterand receiver (TR) probes. It generates the ultrasonic signals and passes over the cross sectional area along thethickness of the graphite plate, receives the pulse echo if any flaw is detected. The flaw will be detected by meansof a pulse echo and the severity of the flaw shall be shown on amplitude reduction. This study established amethodology for first time for ultrasonic testing of graphite plates.

Keywords: Ultrasonic testing, Graphite plates, moderator, pulse echo, TR probe.

IntroductionUltrasonic testing (UT) is the most widely used non-

destructive inspection method for the examination ofcomposites. On microscopically homogenous materials(i.e. non-composite) it is commonly used in the frequencyrange 20 kHz to20 MHz. With composite materials thetesting range is significantly reduced because of theincreased attenuation, so the operating frequency limitis usually 5 MHz or less. However, the ability to resolvesmall flaws will also be reduced and this must be bornein mind. In most techniques short pulses of ultrasound(typically a few microseconds) are passed into thecomposite material and detected after having interrogatedthe structure. The techniques include pulse-echo,through-transmission, back-scattering, acousto-ultrasonics and ultrasonic spectroscopy.

In these methods it is important to avoid frequenciesat which resonance occurs between ply interfaces. Forunidirectional plies spaced at 8 plies/mm this frequencyis usually about 12 MHz. There may be an additionalresonance for woven fabrics at approximately 6 MHzfor 0.25 mm plies, although resonance at otherfrequencies has been seen in practice. In manual

ultrasonic testing (UT) the area is contact-tested byscanning a probe by hand; this is suitable for fieldwork,provided the inspection area is small. Manual UT requiresa high level of operator skill to get consistent resultsbecause the signal amplitude is dependent on thethickness of the coupling fluid layer, which itself isdependent on the pressure applied. However, provided arecognised calibration procedure is carried out, variationsbetween properly trained operators should not pose aproblem. For some composites that are water-sensitiveor absorbent, the use of roller probes with water retentiverubber tyres are preferred as they leave the surface dry.However, these operate at the lower end of the UTfrequency range and therefore are not best suited todetailed defect characterisation.

Procedure

Calibration :

Calibration of Instrument is essential before testingthe actual products. The Calibration also shall be carriedout with international Standards/Procedures. In this casethe instrument was calibrated with an International



Calibration Block as per International Institute ofWelding (IIW) standard and verified for resolution,sensitivity, flaw identity by area, severity, location,quantum, depth and angle of flaw with probe of 0.5 MHz under PET Method in A Scan. The instrument wasused for testing of Graphite plates under Dry Scan Mode.The test parameters are as follows :

System : Dry Scan Sonatest Model: 410 DMethod : Through TransmissionMaterial : Graphite PlatesProbe Diameter : 10 mmProbe specification : STP 10-2Probe Frequency : 0.5 MHzRange : 100 mmVelocity : 5920 m/secMode : T X = R XPRF : 300Delay : 0.00Gain : dB

As per ASTM standards the operator should be acertified person to operate the equipment. A personinvolved in the area of ultrasonic testing on aerospacecomposite products for more than three decades and withUltrasonic Testing Level - II Certification from AmericanSociety for Non Destructive Testing (ASNT) and IndianSociety for Non Destructive Testing (ISNT) has testedthese plates

Test Procedure

The plates were fabricated with Graphite. So it isexpected to have inherent porosity .This porosity causesthe attenuation of sound waves during its actual test.When sound waves travels through a media its intensitydiminishes with distance due to scattering or absorption.Scattering occurs due to inhomogenity. In this scenarioa random test procedure has been carried out by using0.5 MHz frequency, located the lowest scattering andlowest dB loss point. This lowest dB value is used asbest reference parameter by keeping all the parametersof instrument constant except the Gain value. Fig.1a toFig.1c show signal without defect, with partial defect,sever flaw and the instrument used respectively.

Both sides of the Graphite plate were marked in to agrid. The distance between each nodal point of grid is20 mm. The diameter of the Probe is 10 mm for bothTransmitter and Receiver (T R). The ultra sonic signalwas sent through probe to scan the entire product as per

Fig. 1(a) Cumulative signal without defect

Fig. 1(b) Cumulative signal with partial defect

Fig. 1(c) Cumulative signal with sever flaw

the grid nodal points by keeping both the transmitter andreceiver exactly opposite to each other as per the Gridmarked on graphite plate and noted the gain value interms of dB. These tests were carried out before and aftervibration shock tests of graphite plate as a part of criticalapplication.

ResultsTable no.1 shows gain values observed before

environmental (shock & vibration) tests. Aftercompletion of ultrasonic test on fresh Plate it is observed

9V. RAMA KRISHNA et al., ULTRA SONIC TESTING OF GRAPHITE PLATES

that the entire range of product gain values is from 61 to68 dB. Since there is no standard available for this kindof inspection, it was considered that reference gain valueis 61 dB (minimum value). All the individual values arerecorded in a tabular.

Table no. 1

The Graphite plates are subjected to the Vibration testin X, Y and Z directions as shown in fig.2. a, b and crespectively.

For testing the endurance of the plate, these plates aresubjected to vibration as per following specifications

Fig. 2(a) X-direction

Fig. 2(b) Y-direction

Fig. 2(c) Z-direction

Frequency Sweeprange in Hz Amplitude Rate Oct Duration in min

per minuteX-axes Y-axes Z-axes

05-22 1 mm (p-p) 1 60 60 6022-50 2 'g'

After the above vibration tests for endurance, the plateswere inspected .There are no physical damages observedand ultrasonic test was carried out under identicalcondition and parameters of instrument Table no.2 showsgain values observed after vibration test. The testedvalues are recorded and compared with the Ultra sonicReport before Vibration Test.

Table no. 2

This report will be considered as before Shock Testreport. The graphite plates are subjected to the ShockTest as per JSS 55555; a shock of 60g for 8 ms is appliedon the plates. Table no. 3 shows gain values observedafter shock test.


Table no. 3

After completion of Shock Test, There was no physicalDamages observed and Graphite plates are quite intact.

Conclusions(i) A methodology was established for first time for

ultrasonic testing of graphite plates.

(ii) A range of gain values indicate whether theinspected item is normal or flawed.

(iii) For military applications this method can besignificant to check the structures after mandatoryenvironmental tests.

AcknowledgmentsThe authors wish to express their sincere gratitude to

Sri C D Malleswar Scientist 'G', Director, NSTLVisakhapatnam for Permitting to publish this paper.

References1 Dryscan 410D User's Guide, Sonatest UK -June 2009

2 Handbook on Ultrasonics by Chandra Murthy, M/SKalva Engineers Ltd 3rd edition.

3 ASTM E2580 standard approved and published inJuly 2007.

4 JSS 55555 : 2000 standard Revision No 2 -August2000

11O.P. CHIMANKAR et al., COMPARATIVE STUDY OF ULTRASONIC ABSORPTION

Comparative study of ultrasonic absorption and relaxationbehavior of polar solute and non-polar solvent

N.R. Pawar and O.P. Chimankar

Acoustic Research Laboratory, Department of Physics,RTM Nagpur University, Nagpur 440033

*E-mail : [email protected], [email protected]

The ultrasonic absorption has been measured at different frequencies 1 MHz to 10 MHz in the binary liquidmixtures of cyclohexane with cinnamaldehyde and methylmethacrylate over the entire range of composition and atfive different temperatures 293K, 298K, 303K, 308K and 313K. The result has been used to discuss the nature andstrength of intermolecular interactions in the system. In this system structural relaxation plays a predominant roleover thermal relaxation process. The increase or decrease in ultrasonic absorption with increase in molar concentrationis due to the possible structural relaxation process in this binary liquid mixture. These studies may be importantbecause of their extensive use in the engineering, process industries, textile industries, pharmaceutical industriesand nuclear energy industries. Study of propagation of ultrasonic waves and their absorption forms one of the mostimportant methods of investigation of properties of matter in all the three states. It is well known that study ofabsorption of ultrasonic waves in a medium provides important information about various inter and intra-molecularprocesses such as relaxation of the medium or the existence of isomeric states or the exchange of energy betweenvarious molecular degrees of freedom. Ultrasonic absorption and their deviation from the additive rule provide abetter insight into molecular processes. Capsules of cinnamaldehyde are used as food supplements or as dieteticfoods to reduce blood sugar levels in diabetes. Cinnamaldehyde change the structure in drug after some periods.

Keywords: Ultrasonic absorption, relaxation time, viscosity

IntroductionStudy of propagation of ultrasonic waves and their

absorption forms one of the most important methods ofinvestigation of properties of matter in all the three states.It is well known that study of absorption of ultrasonicwaves in a medium provides important information aboutvarious inter and intra-molecular processes such asrelaxation of the medium or the existence of isomericstates or the exchange of energy between variousmolecular degrees of freedom [1-6].

Ultrasonic absorption and their deviation from theadditive rule provide a better insight [7-11] into molecularprocesses. Ultrasonic absorption α can be evaluated fromthe slope of the linear plot of Ln I versus γmean, since themaximum and minimum current are close to each otherγ may be taken as the mean of the γmax and γmin. Whereγmax and γmin are the respective micrometer readingcorresponding to Imax and Imin.

slope = tanθ = 2α .

Hence, α = slope/2. Thus, ultrasonic absorption =slope/2

Hence, Ultrasonic absorption coefficient = α/f2 (1)

Materials and MethodsThe liquids used were of AR grade and were redistilled

in the laboratory. In this study the measurements havebeen made at a temperature 303 K. The temperature ofthe liquid mixture was kept constant by the use ofthermostat U-10 with ± 0.10C accuracy. Densitymeasurement was carried out using specific gravitybottles ± 1×10-5 g/cm3 and digital mono pan-balance withan accuracy of 0.001mg. Ultrasonic velocitymeasurements were made with an ultrasonic multifrequency interferometer at a frequency range 1 MHzto 10 MHz with an accuracy of ± 0.01 m/s. The time ofdescent of the liquid between the viscometer markswas measured using electronic timer with accuracy of± 0.01 s for digital clock.



Result and DiscussionFigure.1 contains the plot of experimental ultrasonic

absorption (α/f2) versus molar concentration at differentfrequencies. It is observed that ultrasonic absorption (α/f2) slightly increases with increase in the molarconcentration of cinnamaldehyde in cyclohexaneindicating more stability of cinnamaldehyde molecules.Cinnamaldehyde molecule has three resonating structurewhich increases the relaxation time. Increase inrelaxation time increases the ultrasonic absorption in thisbinary liquid system. The non-linear variation ofultrasonic absorption in each curve with molarconcentration strongly supports the presence of strongdipole induced dipole intermolecular interactionsbetween the constituent molecules of this binary liquidsystem.

Fig. 1 Variation of (α/f2) versus x at different frequencies

Figure 2 contains the plot of observed experimentalultrasonic absorption (α/f2

obs) versus molarconcentration at different temperatures for 7MHz. It isobserved that ultrasonic absorption (α/f2) slightly

increases with increase in the molar concentration ofcinnamaldehyde in cyclohexane and decreases withincrease in the temperature. The non-linear variation ofultrasonic absorption in each curve with molarconcentration strongly supports the presence of strongintermolecular interactions in the interacting moleculesof this binary liquid system.

The general increase in absorption may be explainedon the basis of energy transfer between different energymodes. The propagation of ultrasonic wave through abinary liquid mixture disrupts thermal and structuralequilibrium of the solution and produces energy transferbetween different modes of the molecules. The increasein ultrasonic absorption with increase in molarconcentration is due to the possible structural relaxationprocess in this binary liquid mixture. These structuralrelaxation processes play very important role in the studyof molecular and structural properties of the componentmolecules in binary liquid mixture. The high value ofviscosity and the relaxation time of component moleculecinnamaldehyde are responsible for increase in ultrasonicabsorption with increase in molar concentration.

The maximum absorption occurs at 10 MHz and for293 K this shows that binary liquid mixture is morestructured at higher frequencies and at lower tem-perature. This higher structured solution generallyabsorbs more ultrasonic energy.

Fig. 3 Resonating structure of Cinnamaldehyde

1 MHz

2 MHz

3 MHz

4 MHz

5 MHz

6 MHz

7 MHz

8 MHz

100959085807570656055504540

(α/f

2 ) X

10–1

5 m–1

s2

0 0.2 0.4 0.6 0.8 1

Molar Concentration (x)

293 K

298 K

303 K

308 K

313 K

100959085807570656055504540

0 0.5 1


(α/f

2 ) X

10–1

5 m–1

s2

Fig. 2 Variation of (α/f2) versus x at different temperaturesFig. 4 Intermolecular Interactions in Cyclohexane

and Cinnamaldehyde

Dipole induceddipole interaction

Dipole inducedDipole interaction

↓CyclohexaneCinnamaldehyde

13O.P. CHIMANKAR et al., COMPARATIVE STUDY OF ULTRASONIC ABSORPTION

Dipole-induced dipole interaction between constituentmolecules and strong hydrogen bond between oxygenatom (O) of cinnamaldehyde and cyclohexane are alsoresponsible for increase in absorption. High value ofviscosity of component molecule cinnamaldehyde is alsoresponsible for increase in ultrasonic absorption.

Figure 5 contains the plot of experimental ultrasonicabsorption (α/f2) versus molar concentration at differentfrequencies. It is observed that ultrasonic absorption(α/f2) slightly decreases with increase in the molarconcentration of methyl methacrylate in cyclohexaneindicating less stability of methyl methacrylatemolecules. Methyl methacrylate molecule has singleresonating structure which decreases the relaxation time.Decrease in relaxation time decreases the ultrasonicabsorption in this binary liquid system. The non-linearvariation of ultrasonic absorption in each curve withmolar concentration strongly supports the presence ofstrong intermolecular interactions between constituentmolecules of this binary liquid system.

Fig. 5 Variation of (α/f2) versus x at different frequencies

Figure 6 contains the plot of observed experimentalultrasonic absorption (α/f2

obs) versus molarconcentration at different temperature for 7 MHz. It isobserved that ultrasonic absorption (α/f2) slightlydecreases with increase in the molar concentration ofmethyl methacrylate in cyclohexane and decreases withincrease in the temperature. The non-linear variation ofultrasonic absorption in each curve with molarconcentration strongly supports the presence of strongintermolecular interactions between interacting

molecules of this binary liquid system.The maximum absorption occurs at 10 MHz and for

293 K this shows that binary liquid mixture is morestructured at higher frequencies and at lower temperature.This higher structured solution generally absorbs moreultrasonic energy. Dipole-induced dipole interactionbetween constituent molecules is responsible for increasein absorption.

Fig. 7 Resonating structure of Methyl methacrylate

Fig. 8 Intermolecular Interactions in Cyclohexaneand Methylmethacrylate

1 MHz

2 MHz

3 MHz

4 MHz

5 MHz

6 MHz

7 MHz

8 MHz

9 MHz

10 MHz

50

45

40

35

30

25

(α/f

2 ) X

10–1

5 m–1

s2

0 0.5 1


Fig. 6 Variation of (α/f2) versus x at different temperatures

293 K

298 K

303 K

308 K

313 K

0 0.5 1


50

45

40

35

30

25

20

(α/f

2 ) X

10–1

5 m–1

s2

Methylmethacylate

Cyclohexane

Dipole – induceed dipoleinteraction


Conclusions1. In this binary liquid mixture absorption process is

due to structural relaxation. These structuralrelaxation processes play very important role in thestudy of molecular and structural properties of thecomponent molecules in binary liquid mixture.

2. Decrease in ultrasonic absorption with increase inthe molar concentration in binary liquid systemscyclohexane and methyl methacrylate are due to lessstability of constituent molecules methylmethacrylate. Because methylmethacrylatemolecules have single resonating structure whichdecreases the relaxation time. Decrease in relaxationtime decreases the ultrasonic absorption.

3. Increase in ultrasonic absorption with increase inmolar concentration in binary liquid systemscyclohexane and cinnamaldehyde are due to morestability of cinnamaldehyde molecules. Moleculesof the cinnamaldehyde has three resonating structurewhich increases the relaxation time. Increase inrelaxation time increases the ultrasonic absorption.

Applications

1. Capsules of cinnamaldehyde are used as foodsupplements or as dietetic foods to reduce bloodsugar levels in diabetes. Cinnamaldehyde change thestructure in drug after some periods. Hence their drugactivity lost and drug is expired. Intermolecularassociation of cinnamaldehyde with cyclohexaneincreases the drug durability.

2. Dissociative property of binary liquid mixture ofcyclohexane and methyl methacrylate enhanced thestrength and rate of production during themanufacture of polymethyl methacrylate acrylicplastics (PMMA) and Methyl methacrylate-butadiene-styrene (MBS).

AcknowledgmentsThe one of the author (OPC) are grateful to University

Grant Commission, New Delhi to providing financialsupport to this work through Major Research Project.

References1 Rath D.C. and Samal K., Study of ultrasonic

absorption in some liquids and liquid mixtures byinterferometric method and applicability of Bauer-Sette theory, J. Pure Appl Ultrason, 16 (1994) 6-10.

2 Rath D.C. and Mahapatra S.C., Study of ultrasonicabsorption in dichloromethane + aliphatichydrocarbons, J. Pure Appl Ultrason, 17 (1995) 50-55.

3 Rath D.C. and Kar P.K.., Intermolecular free lengthand molecular interaction studies in binary mixturesof ketones with aromatic hydrocarbons, J. Pure ApplUltrason, 25 (2003) 58-63.

4 Frank Babick, Frank Hinze and Siegfried Ripperger,Dependence of ultrasonic attenuation on the materialproperties, Colloids and Surfaces A: Physicochem.Eng. Aspects, 172 (2000) 33-46

5 Mehdi Hasan, Ujjan B. Kadam, Apoorva P. Hirayand Arun B. Sawant, Densities, Viscosities, andUltrasonic Velocity Studies of Binary Mixtures ofChloroform with Octan-1-ol and Decan-1-0l at(303.15 and 313.15) K, J. Chem. Eng. Data, 51(2006) 1797-1801.

6 Rama Rao G. V., Viswanatha Sarma A,Ramachanndran D & Rambabu C, Excess transportproperties of binary mixtures of methanol andpyridine through ultrasonic measurements atdifferent temperatures, Indian J. Chem, 46A, (2007)1972-1978.

7 Bandres I, Giner B, Villares A, Artigas H & LafuenteC, Thermodynamic properties of tetrahydrofuran ortetrahydropyran with 1-chlorohexane, Journal ofMolecular liquids, 139 (2008) 138-142.

8 Babak Mokhtarani, Ali Sharifi, Hamid RezaMortaheb, Mojtaba Mirzaei, Morteza Mafi &Fatemeh Sadeghian, Density and viscosity ofpyridinium-based ionic liquids and their binarymixtures with water at several temperatures, J. Chem.Thermodynamics, 41 (2009) 323-329.

9 Pawar N. R., Chimankar O. P. Bhandakkar V. D. &Padole N. N., Study of binary mixtures ofacrylonitrile with methanol at different frequencies,J. Pure & Appl Ultrasonic, 34 (2012), 49-52.

10 Pawar N.R. and Chimankar O.P. Ultrasonicinvestigation of bio-liquid mixtures of methanol withcinnamaldehyde by interferometric method operatedin the frequency range 1 MHz-10 MHz, InternationalJournal of Research in Engineering and Technology(IJRET), 3 (6), (2014) 315-124.

11 Pawar N. R. Ph.D thesis Summary on Investigationof Ultrasonic wave absorption in some Bio-liquids,J. Pure & Appl Ultrasonic, 36 (2014) 69-70.

15P. PALANICHAMY et al., CURRENT RESEARCH IN ULTRASONIC NON-DESTRUCTIVE EVALUATION

Current research in ultrasonic non-destructiveevaluation of materials properties

P. Palanichamy1, M. Vasudevan2 and A. Joseph1

Indira Gandhi Centre for Atomic Research, Kalpakkam - 603 102, INDIA*E-mail : [email protected]

Ultrasonics based nondestructive testing techniques have been effective not only for flaw detection and evaluationpurposes in materials but also for the characterization of materials properties and microstructures. In this paper,some of the important non-destructive research & developmental works carried out at the authors' laboratory on thecharacterization of material properties (microstructures and mechanical properties) in a variety of structural materialssuch as AISI type 316 austenitic stainless steels (SS), modified alloy D9 and Zircaloy-2 are discussed. Potential useof high frequency (>20MHz) ultrasonic measurements for characterisation of precipitation in AISI type 316LN SSthat has a bearing on the properties and performance of the materials in service will be highlighted. Application ofvery high frequency (?1GHz) through scanning acoustic microscopy for various surface and sub-surface imaging ofsensitized microstructures will be discussed.

Keywords: Silver halides, elastic properties, ultrasonic properties

IntroductionNon-destructive testing (NDT) is a very broad and

interdisciplinary field that plays a critical role in assuringthat structural components and systems perform theirfunction in a reliable and cost effective fashion. NDTengineers and technicians define and implement tests thatlocate and characterize material conditions and flaws thatmight otherwise cause planes to crash, reactors to fail,trains to derail, pipelines to burst, and a variety of lessvisible, but equally troubling events. These tests areperformed in a manner that does not affect the futureusefulness of the object or material. In other words, NDTallows parts and components to be inspected andmeasured without damaging them. Because it allowsinspection without interfering with a product's final use.NDT provides an excellent balance between qualitycontrol and cost-effectiveness. Generally speaking, NDTapplies to industrial inspections, while technologies areused in NDT that are similar to those used in the medicalindustry, typically nonliving objects. Nondestructiveevaluation (NDE) is a term that is often usedinterchangeably with NDT. However, technically, NDEis used to describe measurements that are morequantitative in nature. For example, a NDE method would

not only locate a defect, but it would also be used tomeasure something about that defect such as its size,shape, and orientation. NDE may be used to determinematerial properties such as fracture toughness,formability and other physical characteristics.Developments in advanced nondestructive evaluation(NDE) techniques are possible and practicable with theadvent of advanced electronics, innovations in sensortechnology, improvement in the methodologies, etc. Theoutcome of the developments in NDE techniques is theimprovement in fitness for purpose of fabricatedcomponents and their performance in service withpossibility for their life extension. These advantages arebeing effectively utilized by the industries on a regularbasis with rich economic benefits. The NDE technologyhas advanced considerably in India, in tune with the trendworld over to meet the stringent requirements in ensuringthe quality of fabricated components and reliableperformance of plant components in service in nuclearindustry to ensure safety and reliability. In this context,Indira Gandhi Centre for Atomic Research (IGCAR)develops and transfers innovative and advanced NDEtechniques not only to the nuclear industries but also toother strategic and core sectors such as space, defence,



chemical and power. Among the popular NDEtechniques, ultrasonic based techniques are extensivelyused for a variety of materials property characterizationand applied for problems related to quantitative defectevaluation, microstructural characterisation, textureevaluation and residual stress measurements.

It is well known that materials microstructure andmechanical strength are inter-related. Correlations havebeen established between yield strength, grain size andultrasonic attenuation. Basic ultrasonic measurementsviz. attenuation and velocity have been used fordetermination of average grain size; ultrasoniclongitudinal and shear wave velocity measurements havebeen used to obtain degree of recrystallisation, andmeasurement of texture and residual stresses. In recentyears, large numbers of studies were made to evaluategrain size and different microstructures through theprecise measurement of ultrasonic parameters.Ultrasonic NDE of microstructures are also beingconsidered to enable in-situ component monitoringfor both pre-service quality and in-service performances.It is noted that ultrasonic techniques and methodologiesare often superior as compared to other major NDEtechniques such as eddy current, X-ray diffraction, etcfor nondestructive evaluation of microstructures.

Importance of Ultrasonic NDE for Characterizationof Material Properties

The material properties which control metallurgicalcharacteristics are: chemical composition,microstructure, crystal structure and dislocation density.Material properties can broadly be classified asmictrostructural properties and mechanical properties.Conventionally, determination of microstructuralproperties is done by metallography which involvescutting, grinding, polishing and etching. Mechanicalproperties of materials are determined by mechanicaltests like tension tests, Charpy test, etc. These tests beingdestructive in nature are done on coupons or sampleswith an assumption that the coupon is the truerepresentative of the material/components that will gointo service. During fabrication of any component,processes like solidification, mechanical working andheat treatment governs the metallurgical characteristicsand thereby material properties. The conventional samplebased approach of determining material properties maynot be good enough and there may be variation in thethermo-mechanical treatment seen by the coupon andthe component itself. Hence the results of the destructive

tests on coupons may not truly apply to the componentsto be used in service. During service, there are manyfactors, which are adversely affecting the designed lifeof a components leading to its premature failures. Suchfactors include unanticipated stresses (residual andapplied), operation outside designed limits (excessivetemperature and loading), environmental effects anddegradation of material properties in service, etc. It isdifficult to predict the effect of these factors on theservice life of the component to determine its remainingservice life. Therefore NDE characterization of materialproperties assumes a great importance during fabricationas well as in-service life of component. Some of theNDE techniques for material property characterizationare: ultrasonics, X-ray radiography, eddy current,Barkhaussen noise, etc. of which ultrasonics basedNDE play major roles in materials characterization andthe details are discussed in this manuscript.

Ultrasonic NDE is the most preferred NDE techniquesfor characterization of material properties. Beingvolumetric in nature, ultrasonic examination can givean idea about the bulk material properties. Moreover,ultrasonic parameters are significantly affected bychanges in microstructural and mechanical properties ofmaterials. With the advancement electronics andcomputation and ultrasonic instrumentation, theseparameters can be measured very accurately to correlatethem with various material properties with the requiredconfidence levels. Some of the important metallurgicalproperties that have been correlated with ultrasonictesting parameters are grain size, precipitates, elasticmodulus, yield and tensile strengths, residual stresses,etc. Ultrasonic material characterization has also beenused to qualify various processing treatments likeprecipitation hardening, case hardening, etc. and toassess damage due to various degradation mechanismslike fatigue, creep, corrosion, sensitization, etc.Ultrasonic attenuation and velocity are the two basicparameters through which almost all the materialproperties have to be related for the quantitative NDE.Various authors’ define other parameters such asamplitude of back-scatter, critical angles, half width fullmaximum (HWFM), etc. in order to correlate theseparameters with material properties. But these are allonly derived parameters form the ultrasonic basicparameters.

This paper briefly discusses few of the recentdevelopmental works carried out at the authors'laboratory in characterization of microstructures in a


variety of structural materials such as AISI type 316austenitic stainless steels, modified alloy D9 andZircaloy-2. Potential use of high frequency (>20MHz)ultrasonic measurements for characterization ofprecipitation that has a bearing on the properties andperformance of the materials in service will behighlighted. Applications of very high frequency(≈1GHz) through scanning acoustic microscopy(SAM) for various surface/sub-surface imaging ofmicrostructures and defects are also discussed.

Estimation of Average Grain Size in AISI type 316Stainless Steel

Microstructures, especially average grain size ofengineering metals/alloys is an important physicalparameter and it governs the mechanical properties suchas yield strength, fatigue, creep properties, etc. [1-2].Austenitic stainless steels are preferred and used asstructural and core material in Fast Breeder Reactors(FBRs). The knowledge of microstructures of this steelis important to ensure optimum mechanical propertiesof the manufactured components/structures. Amongaustenitic steels, AISI type 316 stainless steel and itsmodified forms are being used for fuel pins clad tubesand hexagonal wrappers in FBR's. Various studies havebeen reported in steels for grain size and other structuralcharacterization by metallography and ultrasonicnondestructive techniques since 1980's [2-6]. The grainsize of a material is an important engineering parameterwhich influences the mechanical properties. Theimportance of the estimation of grain size in apolycrystalline metal/alloy can also be understood fromthe Hall-Petch relation σy = σi + ky/√D where where σyis the yield stress, σo is a materials constant for thestarting stress for dislocation movement (or the resistanceof the lattice to dislocation motion), ky is thestrengthening coefficient (a constant unique to eachmaterial), and D is the average grain diameter. ky is alsoknown as Petch parameter and as unpinning constant[7-8]. Usually grain size is measured either from opticalphotomicrographs or while viewing the microstructureunder a microscope. It is advantageous to use a non-destructive method for the measurement of grain size ofa material since optical microscopic method is timeconsuming and sometimes requires cutting of samplesfrom the material/component. Additionally, the opticalmethod gives the grain size only at the selected locationsand spatial variations, if any, cannot be obtained. In recentyears, various techniques based on ultrasonic attenuation

and velocity measurements have been developed forgrain size measurements. Ultrasonic attenuation andvelocity measurement have been mainly used for thedetermination of grain size [5-7]. Other ultrasonicparameters less used for grain size determination are:first back wall echo amplitude [9], back scattered bulkwave amplitude [3-4], back scattered leaky Rayleighwave amplitude [10] and spectral amplitude of the firstback wall echo [11]. However, average grain sizemeasured as per the procedure given in the ASTMstandard E112 using the linear intercept method has onlybeen taken as the standard for comparison purpose [12].Generally accepted steps involved in the grain sizeestimation using any ultrasonic method are as follows:(i) specimen preparation, (ii) measurement of ultrasonicparameter, (iii) metallographic examination ofspecimens, (iv) generation of calibration or master graphbetween the ultrasonic parameter and the metallo-graphically estimated grain size, and (v) estimation ofgrain size in new specimens to validate the calibrationgraph and also to establish the accuracy.

Sample Preparation, Instrumentation and DataAcquisition

Several specimens having dimensions 50mm diameterand 20mm thickness were heat treated at differenttemperatures (1353K to 1473K) for different timedurations (15 min to 2 hr). These specimens were nextgiven heat treatment at 1323K for 30 minutes followedby water quenching treatment to homogenize the grainstructure [6]. The grain size in these specimens, measuredas per the procedure given in the ASTM standard E112in the range 30-168 µm. Out of which only threespecimens with fine (40µm), medium (85µm) and coarsegrain (148µm) sizes were selected for this study. Figure1 shows the 10 mm thick AISI type 316 stainless steelsamples actually used for all type ultrasonic studies

Fig. 1. AISI type 316 stainless steel (SS) samples of 10 mmthick (approx.) used for ultrasonic studies (averagegrain size in the range 30 - 150 µm).


Fig. 2. Photomicrographs of the stainless steel specimens(a) 30 µm, (b) 78 µm and (c) 138 µm.

a b c

Fig. 3. Photomicrographs of the stainless steel specimens(a) 30 µm, (b) 78 µm and (c) 138 µm.

500 MHz Digitizing Oscilloscope

35 MHz broad bandpulser receiver

Transducer

SpecimenCouplant

Personal computerwith LabVIEW

software

Fig. 4. Correlation of attenuation coefficients as function of metallographically obtained average grain size in AISI type 316 SS(a), Longitudinal ultrasonic velocity Vs Average grain size of SS (b), Comparison between grain sizes of SS obtained bylongitudinal wave velocity and metallography.

15 MHz

10 MHz

6 MHz

5 MHz

4 MHz

10

10

10–1

10–2

5020 90 130 190GRAIN SIZE (µM)

AT

TE

NU

AT

ION

CO

EFF

ICIE

NT

(dB

/mm

)

LO

NG

ITU

DIN

AL

WA

VE

VE

LO

CIT

Y m

/sec

,

GR

AIN

SIZ

E, µ

m (L

ON

GIT

UD

INA

L W

AV

EV

EL

OC

ITY

)

GRAIN SIZE, µm(METALLOGRAPHY)

AVERAGE GRAIN SIZE, µm

60 80 100 120 140 160 180 10 20 30 40 50

150

140

130

120

110

5690

5680

5670

5660

including ultrasonic attenuation, velocity, spectralanalysis, etc. studies. Figure 2 shows the microstructuresof three samples viz. fine grain, medium coarse grainpolycrystalline structures determined by metallography.Figure 2 shows the schematic experimental arrangementfor the ultrasonic A-scan data acquisition from thesamples using 20 mm diameter broad band 2 MHz normalbeam longitudinal wave transducer. A minimum of 10A-scan signals for each sample was acquired for thepurpose of ultrasonic attenuation, velocity measurementsand other studies.

As early in mid-80's we have made initial contributiontowards the application of ultrasonic attenuationmeasurement technique for the quantitative estimationof average grain size in AISI type 316 SS. Figure 4ashows the typical metallographicaly obtained grain sizeversus attenuation coefficient graph for the longitudinalwave ultrasonic frequency range 2-15 MHz. Figure 4bis the master graph established between ultrasonicvelocity at 4 MHz with average grain size in AISI type316 SS. Figure 4c represents the one to one corres-pondence between ultrasonically obtained grain size withmetallographically determined average grain size

Comparison of Different Ultrasonic Methods forGrain Size Determination

Comparison of ultrasonic attenuation (UA)measurements made at different frequencies (Fig. 4)shows that measurements made using 4MHz longitudinal


wave transducer gave better results for the grain sizeestimation [5] in the range 30-150 µm. Problemsconnected with the attenuation method such as couplantand diffraction corrections are eliminated in the methodbased on ultrasonic relative attenuation (URA).Measurements with a 10MHz immersion transducer gavethe best result and this is a first of its kind approach. Theauthors have used ultrasonic velocity (UV)measurements for the first time for the grain sizedetermination. Accurate velocity measurements at 2MHzwere made for longitudinal and shear waves using pulseecho overlap technique. A linear relationship was foundto exist between the velocity and the metallographicallyestimated grain size (Fig. 4b) Unlike the attenuation andfirst back wall echo amplitude methods, velocitymeasurements were also found to be less affected bychanges in the grain size distribution. For the estimationof only surface/subsurface grain size, a method basedon the measurement of the amplitudes of the backscattered leaky Rayleigh wave (LRW) was employed.Results indicated that confidence level of 75% only couldbe achieved using conventional attenuation method andthe repeatability of the measurement data was also foundto be poor. Measurements using first back wall echoesand LRW amplitudes gave better than 80% confidencelevel. It was found that best confidence level of 85% inthe grain size estimation was achieved using velocitymeasurements (Fig. 4c).

As compared to the longitudinal waves, shear waveswere found to be more sensitive in grain size estimationusing the velocity measurements. Selection of properfrequency also plays an important role in grain sizeestimation by different methods. These studies showthat: (i) Ultrasonic methods can replace time consumingmetallographic methods for grain size estimation. (ii)URA method is most useful for coarse grained and thickstainless steels. The method is also amenable for

continuous measurements in production line. (iii) Methodbased on velocity measurements is best for achievinghigher accuracy level in grain size measurements. Thisalso less influenced by variation in grain size distribution.Recently, method based on ultrasonic spectral approach(USA), a shift in the peak frequency due to grain sizevariation has also been proposed and advantage of thismethod in average grain size determination is thatvariation in couplant thickness does not affect the results.Qualitative performance of all ultrasonic based methodsin comparison with metallographic method issummarized in Table 1.

Note : UA - Ultrasonic attenuation method; UB -Ultrasonic backscattering; URA - Ultrasonic relativeattenuation; LRW - Leaky Rayleigh wave; UV -Ultrasonic velocity; USA - Ultrasonic spectral approach

Precipitation Studies in Nuclear Grade AISI Type316LN Stainless Steel [13]

Nitrogen alloyed austenitic stainless steels haveemerged as candidate materials for a variety ofengineering applications by virtue of their superiormechanical and chemical properties as compared to otheraustenitic stainless steel grades such as 304L, 304 and316. The vastly improved properties of nitrogen alloyedsteels result from the higher binding energies of nitrogenwith chromium and greater pinning effects ofdislocations, compared to carbon steels. Addition ofnitrogen leads to stronger influence of the thermomechanical history and the microstructures on thematerial properties, since the thermo-mechanical historycontrols the nitrogen distribution in the steel. In order toensure desired mictrostructural state, basic understandingon the nitrogen role in the various aspects ofmicrostructural parameters and mechanical properties isvery essential. In addition to optical and electron

Table 1: Performance of ultrasonic based methods in comparison with metallography on the determination of average grain size inAISI type 316 SS

PROPERTY UA UB URA LRW UV USA Metallography

Volume Analysis Yes No Yes No Yes Yes PossibleStandard Offing No No No No No YesInstrumentation Less costly Costly Moderate Moderate Moderate Costly CostlyCoarse Grain Yes Possible Best Best Good Better BetterThicker Specimen Poor Best Best Better Better Poor BetterOnline Measurement No Possible Best Possible No Possible NoCorrection Factors Yes Yes No No No No Not applicableConfidence Level 70% 75% 80% 80% 85% 75% Standard


microscopy, ultrasonic measurements carried out tocorrelate the microstructural features with ultrasonicparameters. The various stages of repartitioning ofnitrogen and precipitation of nitrides in nuclear grade316LN stainless steel on ageing at 1123K have beencharacterized using transmission electron microscopy(TEM). The formation of Cr N clusters on aging for 10h,followed by intra granular precipitation of coherent Cr2Nbeyond 25h and finally the cellular precipitation of Cr2Nand formation of chi phase beyond 500h have been wellcharacterized and reported [14-16]. Here an attempt hasbeen made to correlate these microstructural changeswith ultrasonic velocity measurements

Figure 5 shows the variation in ultrasonic velocity withageing treatment for ultrasonic longitudinal wavefrequencies 5, 10, 50 and 75 MHz. It is seen thatultrasonic velocity increases up to 25h with ageing. Onfurther ageing at the same temperature till 2000h, thevelocity decreases. No difference in the trends wasobserved between the velocities increased at the fourfrequencies studied. The increase in velocity during 10hof ageing (Stage-A) is mainly associated with matrixeffects. Formation of Cr-N rich clusters after 10h ofageing, leaves behind a relatively nitrogen depleted andconsequently strain free matrix. Formation of coherentintragranular Cr2N precipitates on ageing up to 25h isalso associated with a small increase in velocity (Stage-B). This can be attributed mainly due to modulus effects,

arising from the large elastic moduli difference betweenthe matrix and the precipitate. Formation of cellularprecipitates beyond 500h and coarse chi phases beyond1000h result in increased scattering at the precipitate/matrix interface boundaries and thereby decrease theultrasonic velocity (Stage-C). A larger decrease invelocity with increasing frequency of ultrasonic wavesin Stage-C, can be seen from Fig. 5. This is because, asthe ultrasonic frequency is increased from 5 MHz to 50MHz, the wavelength decreases by about 10 times. Thehalf wavelength of 50 MHz ultrasonic waves being about58 ?m is almost equivalent to the austenite grain size.Since the cellular precipitate extend over the entire grain,a 50 MHz wave would have greater probability ofinteracting with these precipitates and consequentlywould undergo greater scattering in comparison to 5 or10 MHz wave. The significant difference between thevelocities of the waves with different frequencies,particularly beyond 500h of ageing as seen from Fig. 5can be understood well. TEM studies carried out onevolution of microstructural features in these steelscarried out earlier correlate well with the ultrasonicmeasurements [14-16]. The analysis of the presentwork suggests that ultrasonic evaluation may be a handytool to study the precipitation reaction involvinginterstitial elements like nitrogen, and associated withlarge changes in the lattice strains

Fig. 5. Ultrasonic velocity as function of ageing time in AISI type 316LN SS. 'A' refers to frequency independent modulus-dependent velocity change, 'B' refers to frequency dependent velocity change and 'C' refers to scattering induced velocitychange.

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/s

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Annealing Behaviour of Cold Worked Alloy D9 [17]Recovery, recrystallisation and grain growth are the

three stages in annealing processes, which bring out thechanges in the cold worked microstructure. Among thesestages, recrystallisation is the microstructural process bywhich new strain free grains form from the deformedmicrostructure. Depending on the material, therecrystallisation process is often accompanied by othermicrostructural changes like decomposition of solidsolution, precipitation of second phases, phasetransformations etc. in addition to recovery and strainfree grain formation. These changes influence the kineticsof recrystallisation and often mask the picture revealedby certain methods of analysis. The most commontechniques used to study annealing behaviour of metalsand alloys are the hardness testing, optical and electronmicroscopy. The techniques of hardness measurementand optical metallography often found to give differentvalues for the temperature or the time at which therecrystallisation process either starts or is completed.Quantitative metallography techniques, which areoften used to measure the extent of the recrystallisationprocess, are time consuming and error prone. In thiswork, ultrasonic velocity measurement techniquehas been used to characterize the progress ofrecrystallisation.

Ultrasonic velocity measurements using 4MHz shearand longitudinal waves were carried out in 20% coldworked (tensile pulled) and annealed specimens of 15Cr-

15Ni-2.2Mo-Ti modified austenitic stainless steel (alloyD9) to characterize the isothermal and isochronalannealing behaviour. Figure 6 shows the variation inlongitudinal velocity with annealing time. VL1 is thevelocity along the tensile stress pulling direction and VL2is the velocity perpendicular to the tensile stress pullingdirection. The velocity exhibits a slight increase in therecovery region followed by a sharp and continuousdecrease in the recrystallisation region and reachessaturation on completion of recrystallisation (Fig. 6).Increase in the velocity in the recovery region is due tothe reduction in the distortion of the lattice in comparisonto the cold worked condition. The sharp decrease in thevelocity during recrystallisation is attributed to thechange in the texture. Further annealing treatment showssaturation in velocity. Thus velocity is found to besensitive to the different microstructural changes takesplace during recovery, recrystallisation and saturation.Similarly, shear wave velocity measurements have alsobeen carried out preciously. VS1 is the shear wavevelocity in the direction of stress and VS2 and VS3 arethe shear wave velocities measured perpendicular to thedirection of stress with their polarization parallel andperpendicular, respectively to stress direction.

Figure 7 represents the variation of shear wave velocityparameters as function of annealing time. The velocityparameter, which is a combination of the shear wavevelocities, measured in the transverse direction withpolarization directions parallel and perpendicular to the

Fig. 6. Variation of ultrasonic velocity with annealing time at1073K in 20% cold worked Alloy D9.

Fig. 7. Variation of velocity ratio parameter and the fractionun-recrystallized microstructure as a function of an-nealing time at 1073K in Alloy D9.

0.1 1 10 100 1000

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cold worked direction is found to closely represent theextent of progress of recrystallisation (Fig. 8), asmeasured by optical metallography. It has also beenverified that velocity measurements could sense theonset, progress and completion of recrystallisation moreaccurately compared with that of hardness and strengthmeasurements (Figs. 8-9). The advantage of usingvelocity parameters is that it avoids the stringentmeasurement of material and thereby eliminates thedifficulties and the errors associated with thickness

measurements. Figure 10 shows the variation in velocityratio parameter with fraction of recrystallisedmicrostructure.

This would be useful approach for on-line monitoringof microstructures in the production environment usingvelocity ratio parameters. In case of manufacturedcomponents under service conditions, these parameterswould be again useful for continuously monitor toidentify any change in the original microstructural stateof the material without affected by the any local variationin the material thickness.

Assessment of Hard Intermetallic Phases in Zircaloy-2 [18]

Zirconium alloys are important materials for corecomponents of pressurised heavy water reactors(PHWRs). Among various zirconium alloys, Zircaloy 2is used for fabrication of fuel cladding tubes, calandriatubes and pressure tubes of these PHWR reactors. Oneof the steps in fabrication of Zircaloy 2 components isthe β-quenching of the hot extruded billets. β-quenchingtreatment is given to Zircaloy 2 to homogenize thechemical composition and randomize the texture.Improper β-quenching treatment results in theprecipitation of hard intermetallics and α-phase and thusinterferes with further forming operations thus leadingto rejection of the final fabricated products.

Ultrasonic velocity measurements carried out in thefrequency range 10 to 25 MHz showed a decreasing trendwith ageing temperature up to 773K and further increase

Yie

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Fig. 9. Variation of yield strength and ultrasonic velocity asfunction of annealing time.

Fig. 10. Variation of velocity ratio parameter with extent ofrecrystallisation.

0.06

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Fig. 8. Variation of hardness and ultrasonic velocity asfunction of annealing time.

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in ageing temperature indicated increase in the ultrasonicvelocity (Fig. 11). Hardness measurements indicated anopposite trend to the velocity measurements i.e. anincreasing trend up to the ageing temperature of 773Kand beyond this temperature, a decrease in the hardnesswas observed (Fig. 11). The higher hardness in theintermediate temperature range is attributed toprecipitation of hard intermetallics. Ultrasonic velocitymeasurements at 50 and 100 MHz frequencies indicated

that at 50 MHz, decreasing trend in velocity was observedup to 873K and further ageing showed increase invelocity (Fig. 12) [18]. This is similar to that observedat lower frequencies, except for the extent of variation.However at 100 MHz frequencies, measurementsshowed a continuous decrease in the velocity with ageingtemperature. This continuous decrease in the velocity athigher frequencies in specimens aged at highertemperatures has been attributed to the dissociation ofβ-quenched martensite and formation of small size andisolated α-phase at higher temperatures.

At lower frequencies, absence of continuous decreasein velocity beyond 873K is attributed to long wavelengthof the ultrasonic waves and hence lacks of appreciableinteraction between ultrasonic waves and the small sizeand isolated α-phase. These studies demonstrate thatwhile the low frequency velocity measurements arecapable of revealing the presence of hard intermetallics,high frequency velocity measurements are useful forrevealing the early stage dissociation of β-quenchedmicrostructure to α-phase.

Ultrasonic attenuation measurements were alsocarried out at low frequencies (2 and 10MHz) and athigher frequencies (25, 50 and 100 MHz), respectivelyin specimens at different ageing temperatures [19]. Thechange in the attenuation due to ageing is marginal at 2MHz. At all other frequencies, variation in the attenuationwith ageing temperature generally shows an oppositetrend to that of the velocity i.e. an increasing trend in theattenuation with ageing temperature and reaches a peakat 873K and beyond that, attenuation decreases at furtherageing temperature (973K). The scatter-band for lowfrequency attenuation measurements is high, i.e. 0.04dB/mm even in the case of immersion type measurementsand hence low frequency attenuation measurementscannot be employed reliably for characterization ofdifferent microstructures in the β-quenched and agedspecimens. However, the scatter band in the attenuationmeasurements at higher frequencies (25, 50 and 100MHz) is relatively less, i.e. 0.005 dB/mm and theobserved trend can reliably be taken into account forinterpreting the results with respect to the changes in themicrostructure. The increasing trend in the attenuationup to 873K is attributed to precipitation of hardintermetallics. Subsequent reduction in the attenuationat 973K is attributed to reduce amount of precipitationof intermetallics at higher temperatures. The reductionin the attenuation occurs in spite of precipitation of asmall amount of α-Zr.

Fig. 11. Ultrasonic velocity and hardness as a function ofageing temperature β-quenched Zircaloy-2.

Fig. 12. Variation of ultrasonic velocity with ageingtemperature for 25, 50 and 100 MHz ultrasonicfrequencies in β-quenched Zircaloy-2.


Application of Scanning Acoustic Microscopy forCharacterisation of Materials Microstructures

It is well known that, it is the microstructure of thematerial that controls the bulk properties. These bulkproperties are mainly elastic properties. Many a time,optical and electron optic micrographs will not beadequate since they will not provide the information onthe elastic properties of the constituents of themicrostructure. Scanning acoustic microscope (SAM)will precisely meet this requirement. In 1949 Sokolov[20] put forward the concept of Acoustic Microscopy.Later concept was developed by Lemons and Quate [21]in the year 1974 (Stanford university). Acousticmicroscopy (AM) is a recently developed method forcharacterization of microstructure. AM is used to revealdensity, morphological and microelastic propertyvariations in the image domain. Acoustic/ultrasonicimaging is the important tool for materialscharacterization. AM is analogous to optical reflectionor transmission microscopy and it do not require anyrigorous sample preparation such as etching, polishing,sectioning etc., as in traditional microscopy. Using SAM,one can measure the acoustic properties of microscopicfeatures like grain boundaries, second phases such asprecipitates and inclusions and correlate them with bulkmaterial properties. SAM can also be used for studyingsurface and sub-surface imaging of defects, sensitizedmicrostructures, grain clusters, texture and strain fields,recrystallisation, phase change/ transformation, wavevelocity (longitudinal and Rayleigh) in miniaturespecimens and elastic constants in micro specimens.Understanding SAM images needs considerableexpertise on the expected acoustic contrast. There areseveral techniques for acoustic microscopy, of which theSAM is unique in its image quality and resolution. Byconsidering the application of SAM in materialscharacterization, attempt has been made to explain thebasic principle, working and the different applicationsof SAM.

Working Principle of SAM :

The heart of the acoustic microscopy is the sapphirelens and at the back surface of the sapphire lens, apiezoelectric transducer is fixed. A short RF pulse isapplied to the piezoelectric transducer, resulting in thepropagation of acoustic pulse down the sapphire rod.The acoustic pulse is focused into the coupling liquid bythe sapphire lens as shown in Fig.13. The focusedacoustic pulse gets reflected back from the object, whichis to be imaged. In acoustic microscope, there are two

modes of operation. In the first mode of operation namelyreflection mode, the imaging object is placed at the focusof the sapphire lens. Therefore, the reflected acousticwaves return along the incident paths. Further, thereflected waves are converted into an electrical pulse bythe transducer. The strength (amplitude) of the reflectedpulse depends on the object being investigated. Thus,the amplitude is measured and is used to modulate thebrightness of the display. In order to get the image of theobject, the lens is scanned in raster pattern over thespecimen. In the second mode i.e., the transmission mode,acoustic waves are transmitted through the object understudy. The strength of the emerging waves on the otherside of the object is used to study the object nature. Inthe reflection mode, the microscope is used to image thesubsurface features, while in the second mode it is usedto study the interior of thick specimens. The reflectionmode is more popular than transmission mode. Due tothe advancement in the field of electronics, the instrumenthas now possessed a high degree of sophistication. Thecommonly available range of resolution is 500 m to 20nm. The operating frequency range of SAM is 50 MHzto 1 GHz.

Acoustical material signature 'V(z)' Curve

In order to characterize these materials the SurfaceAcoustic Wave (SAW) speed in the materials has to bemeasured. The SAM is based on the principle of variationof amplitude and phase with the distance between theacoustic microscope lens and the specimen, generallycalled acoustical material signature or V(z) effect. TheSAW is measured from the V(z) curve i.e., voltage versusdefocus distance z, by moving the microscope lens

Fig. 13. Basic lens geometry for reflection acousticmicroscopy.

Circular

OUTPUTINPUT

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Al2O

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vertically normal to the reflecting surface. The reflectedsignal voltages are recorded and it lies between a seriesof maxima and minima as the lens-specimen distance isvaried. The observed maxima and minima are due to thephase difference between the central ray and thenonspecularly reflected critical ray that varies with thelens-specimen distance as shown in Fig.14.

The technological development finds wide applicationfor the NDE community for characterization of bothisotropic and anisotropic materials. The development ofthe line focus acoustic lens finds application to studythe anisotropic materials through acoustic microscopy.The materials, which are characterised through acousticmicroscopy are AISI type 316 LN and a non-metallicmaterial granite.

Application of SAM to Sensitization Studies in AISIType 304 LN :

Sensitisation, in the strict sense means chromiumcarbide precipitation, which in turn make the materialsensitive to intergranular corrosion (IGC). Thephenomenon of sensitization is of great practicalsignificance because of thermal exposures duringwelding, fabrication, heat treatment etc. produce themetallurgical condition susceptible to intergranularattack. Austenitic stainless steel, such as AISI type 304LN is candidate material for fast breeder reactorapplications. This steel is used as fuel pin material underthe 20% cold worked condition. However, the materialgets sensitized when it is slowly cooled through thetemperature range 450 - 850 °C or isothermally treatedin the above range [22-23]. Sensitization brings down

the mechanical, creep and corrosion properties of thecomponents made out of this steel. Hence systematicstudies mainly using metallographic techniques areusually followed for monitoring sensitization. However,metallographic techniques are time consuming anddestructive. Moreover, metallographic techniques do notprovide depth information. Hence SAM studies havebeen undertaken for the evaluation sensitized propertiesof AISI type 304 LN.

(a) Optical image of the polished sample

(b) SAM image of the polished sample

(c) Optical image of the etched sample

Fig. 15. Images of the not sensitized 304LN sample

Figure 15(a) shows the optical image of the polishedsurface of the not sensitized sample. Figure 15(b) showsthe SAM image obtained by raster scanning at 850 MHzmid frequency and Fig. 15(c) represents the optical imageof the etched AISI 304 LN not sensitized sample. Figure16(a) shows the optical image of the polished sensitized

1.2

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ized

V(z

)

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50 µm


sample. Figure 16(b) shows the SAM image obtainedby raster scanning at 850 MHz mid frequency of thesensitized sample. Figure 16(c) represents the opticalimage of the etched AISI 304 LN sensitized sample aboutthe temperature 700°C for 100 hrs. The SAM imagesreveal the broadening of the grain boundaries insensitized sample, which is due to the formation of thechromium carbide precipitation along the grainboundaries.

(a) Optical image of the polished sample

(b) SAM image of the polished sample

(c) Optical image of the etched sample

Fig. 16. Images of the sensitized 304 LN sample.

Sensitization brings down the mechanical, creep andcorrosion properties of the components made out of thissteel. Hence systematic studies mainly usingmetallographic techniques are usually followed formonitoring sensitization. However, metallographictechniques are time consuming and destructive.

Moreover, metallographic techniques do not providedepth information. Hence SAM studies have beenundertaken for the evaluation sensitized properties ofAISI type 304 LN.

Figure 17 show the sub-surface SAM images obtainedfor the same mid band frequency 850 MHz but havingthe defocusing at Z = 10.3µm. The grain boundaries aredistinctly different due to the effect of sensitization. Inthe sensitized microstructure broadening of the grainboundaries take place due to the effect of stress relaxationby the depletion of chromium to the gain boundaries andthe formation of chromium carbides at the boundaries.The strain created at the grain boundaries are seen asfringes.

Fig. 17. SAM Image defocused at Z=10.3 µm of the notsensitized and sensitized AISI 304LN

Summary and Conclusion

An overview on the usefulness of ultrasonic velocityand attenuation measurements for characterisation ofmicrostructures in austenitic stainless steels and Zicalloy-2 has been discussed. Various ultrasonic based on wavedecay and wave speed has been established for thequantitative determination of average grain size in AISItype 316 austenitic stainless steel. Studies made innuclear grade 316LN stainless steel reveals thatultrasonic evaluation may be a handy tool to study theprecipitation reaction involving interstitial elements likenitrogen that are associated with large changes in thelattice strains. Ultrasonic velocity measurements madein the annealed specimens of 20 % cold worked alloyD9 can sense onset, progress and completion ofrecrystallisation more accurately as compared by that ofhardness and strength measurements. Ultrasonic velocitymeasurements performed in β-quenched treated and agedZircaloy-2 specimens reveal the capability of velocitymeasurement technique in detecting the presence of hardintermetallics.

Not


Scanning Acoustic Microscope is a non-destructiveanalytic tool using ultrasonic waves. In the acousticsignature mode (quantitative mode), the elasticparameters is evaluated. In the imaging mode (qualitativemode), the grain structure is revealed due to variation inthe acoustic impedance across the matrix without etching.The contrast in the image is from the variation in elasticconstant contributing from the different phases in thematrix. Assessment of the subsurface defects, such ascrack, inclusions, voids etc is possible, which makes it aversatile technique in non-destructive testing. In case ofsensitized AISI type 304 LN, grain boundaries are moredistinctly revealed by SAM images both at surface andsub-surfaces.

Acknowledgements

The authors are thankful to Dr. T. Jayakumar, Director,Metallurgy and Materials Group and Dr. B.P.C. Rao,Head, Nondestructive Evaluation Division, Indira GandhiCentre for Atomic Research, Kalpakkam, for theirsupport and encouragements.

References1 Papadakis E.P., Physical Acoustics and

microstructures of Iron Alloys, International MetalsReviews, 1 (1984) 1.

2 Vary A., Ultrasonic Measurements of MaterialProperties, In "Research Techniques in NDT", Ed.R.S. Sharpe, Academic Press, London, 4 (1990) 189.

3 Hecth A., et al., Nondestructive Determination ofgrain size in austenitic stainless steel by ultrasonicback scattering, Materials Evaluation, 39 (1981) 934.

4 Williams H. and Goebbles K., Characterisation ofmicrostructures by back scattered ultrasonic waves,Metal Science, 15 (1981) 549.

5 Palanichamy P., Subramanian C.V., Barat P.,Bhattacharya D.K. and Baldev Raj, A NDT methodfor grain size determination in austenitic stainlesssteel, Trans. IIM, 41(5) (1988) 485.

6 Palanichamy P., Joseph A., Jayakumar T. and BaldevRaj, Determination of average grain size in austeniticstainless steel by ultrasonic velocity measurements",NDT & E International. 28(3) (1995) 179.

7 http://www4.ncsu.edu/~murty/NE509/NOTES/Ch5d-Strengthening.pdf

8 Klinman R., Webster G.R., Marsh F.J. andStephenson E.T., Mater. Eval., 38, (1980) 26.

9 Palanichamy P., Joseph A. and Jayakumar T., Insight,36(11) (1994) 874.

10 PalanichamyP. and Jayakumar T., Grain SizeMeasurements by Ultrasonic Rayleigh SurfaceWaves, 14th WCNDT, New Delhi, India, (1996) 8.

11 Anish Kumar, Jayakumar T., Palanichamy P. andBaldev Raj, Influence of grain Size on UltrasonicSpectral Parameters in AISI Type 316 Stainless Steel,Scripta Materiala, 40(3) (1999) 333.

12 ASTM Standard E112-10, Standard Test Methodsfor Determining Average Grain Size, Annual Bookof ASTM Standard, 03.03, (2010).

13 Shankar P., Palanichamy P., Jayakumar T. and BaldevRaj, Met. Mater. Trans., 32A, (2001) 2959.

14 Shankar P., Sundararaman D. and Ranganathan S.,Scr. Metall. Mater. Trans., 31 (1994) 589.

15 Sundararaman D., Shankar P. and Ranganathan S.,Metall. Trans., 27A (1996) 1175.

16 Shankar P., Sundararaman D. and Ranganathan S.,J. of Nucl. Mater., 254 (1998) 1.

17 Palanichamy P., Vasudevan M., Jayakumar T.,Venugopal S. and Baldev Raj, NDT&E International,33 (2000) 253.

18 Jayakumar T., Palanichamy P. and Baldev Raj, J.Nuc. Materials, 255 (1998) 243.

19 Jayakumar T., Palanichamy P. and Baldev Raj,"Acoustic methods for characterisation ofmicrostructures and deformation processes inNimonic alloy PE 16 and Zircaloy 2", MineralProcessing and Extractive Metallurgy Review, 22(2001) 249.

20 Sokolov S., The ultrasonic microscope, DokladyAkademia Nauk SSSR (in Russian) 64 (1949) 333.

21 Lemons R.A. and Quate C.F., Appl. Phys. Lett., 24(1974) 163.

22 Kamachi Mudali U., Babu Rao C. and Baldev Raj,Corrosion Science, 48(4) (2006) 783.

23 Mularleedharan P., Gananamoorthy J.B. andRodriguez P., Corrosion, 52 (1996) 790.

28 J. PURE APPL. ULTRASON., VOL. 36, NO. 2-3 (2014)

The D.Phil. thesis focused on physics and chemistryof nanostructures e.g. nanofibers, nanotubes, sphericalnanoparticles based nanofluids and nanocompositesleading to their applications as heat transfer basedcoolant liquids and dielectric materials with better heatconduction. Ultrasonic and thermal conductivitybehaviour of synthesized materials has been studied ina wide range of temperatures and other variablephysical conditions. When propagated in materials,ultrasonic waves are influenced by the microstructure,structural inhomogeneities, nonlinear thermal/physicalproperties, reinforcement level of particles innanocomposites, size and distribution ofreinforcements, surface phenomenon etc. The attentionhas been paid on the ultrasonics based non-destructivecharacterization of the prepared materials.

The whole work presented in the thesis was dividedinto seven chapters. In the chapter-2, different ultrasonicand thermal experimental techniques used for the non-destructive characterization have been discussed.Chapter-3, 4 and 5 presented our experimental studyon Polyaniline nanofibers, MWCNTs and NiOnanoparticles based nanofluids and their ultrasonic andthermal conduction behaviour. In the study, synthesis,characterization and possible applications are discussedin details. These studies are done in a wide range oftemperature (10-90°C) as temperature is a crucialparameter for the heat transfer applications. Further,time dependent stability is investigated in thesenanofluids. Maximum thermal conductivityenhancement ratio in synthesized Polyaniline-Waternanofluids is 140 % with 0.24 vol % of nanofibersloading at 80°C temperature. This enhancement wasobserved due to better crystallinity and morphologicaluniformity of synthesized PANI nanofibers. For thecase of MWCNT-Water nanofluids, anomalousenhancement was started at very small concentrationof 0.03 vol % MWCNT loadings in base fluid. Thus,

it can be claimed that the predicted percolationthreshold is detected in MWCNT nanofluids. Furtherthe NiO nanoparticles was synthesized with the particlesize in the range of 18-25 nm and their nanofluids inEthylene Glycol fluid matrix via chemical route. Theparticle size distribution in these nanofluids wasdetermined with ultrasonic spectroscopic technique.There was a strong correlation between temperatureand concentration dependent variation of ultrasonicvelocity and thermal conductivity of the nanofluids.The maximum thermal conductivity enhancement(205% at 80°C) due to dispersion of nanoparticles wasobserved in the NiO-EG nanofluids. Chapter-6 isdevoted to the preparation of Polyaniline nanofibersbased epoxy nanocomposites along with thecharacterizations of materials systems leading to thedielectric applications. It was established that ultrasonicvelocity can be utilised for the determinationlongitudinal modulus composite materials likePolyaniline nanofibers in epoxy matrix. The behaviorof phonon mean free path, ultrasonic attenuation andthermal conductivity with reference to particle loadingwas correlated. Behavior of temperature dependencyof ultrasonic attenuation and thermal conductivityprovided the information about thermal relaxationphenomenon. The employed theoretical approaches forthe ultrasonic attenuation and the thermal conductivityhave been explained successfully the experimentalobservations.

In view of above, final objective of the thesis was toestablish the ultrasonic mechanism/method that ensuresuseful, important information about the synthesizednewly class materials systems to be extracted from thecorrelations established between the ultrasonicproperties and the role of particles size, concentrationof the particles in matrix, other physical propertiessuch as thermal conductivity due to nano-structuringin the nanocomposites/nanofluids.

D.Phil. Thesis SummarySynthesis and Ultrasonic Characterization of Nanoparticles

Based Advanced Materials and Their Applications

(D.Phil. degree is awarded to Dr. Meher Wan by University of Allahabad, 2015)

Dr. Meher WanPost Doctoral Fellow

Department of Metallurgical and Materials EngineeringIndian Institute of Technology, Khargpur-721302, India

E-mail : [email protected]

29CONFERENCE REPORT (ISU-2015)

The International Symposium on Ultrasonics (ISU-2015) was organized during 22-24 January 2015 byDepartment of Physics, R.T.M. Nagpur University,Nagpur jointly with Ultrasonic Society of India (USI).The venue of the symposium was BSNL RegionalTelecom Training Centre (RTTC), Seminary Hills,Nagpur. Shri Mathuradas Mohota Science College,Shivaji Science College, and Institute of Science, all atNagpur, were the co-hosts. The symposium wassponsored by DST, DRDO, UGC, RTM NagpurUniversity and Mittal Enterprises, New Delhi.

The Inauguration of ISU-2015 was held in the graciouspresence of Prof. Manell E. Zakharia, InternationalTechnical Expert, French Embassy ( and Ex-PresidentFrench Acostical Society of India) and Prof. VikramKumar, President USI. Dr. Mahavir Singh, GeneralSecretary USI, Prof. Vilas A. Tabhane, DistinguishedProfessor, Pune University & Chairman ISU-2015, Dr.Kishor Ghormare, Chairman, BoS Physics, RTMNU,Prof. S. Rajgopalan, Ex-Head of the Department ofPhysics, RTMNU, Prof. Dr. P. M. Gade, Head,Department of Physics, RTMNU were guests of honor.Dr. O. P. Chimankar, Convener ISU-2015 and Dr. S. G.Charalwar, Principal, S. M. M. Science College & alsothe Co-Convener shared the dais.

Dr. O. P. Chimankar, Convener welcomed the guestsand the delegates and introduced the aims and objectivesof the symposium. He elaborated the focal theme of thesymposium "Ultrasound in Biomedical and IndustrialApplications". Lifetime achievement awards werepresented to the eminent personalities Prof Vilas A.Tabhane, Prof. B.A. Patki and Prof. S. Rajgopalan fortheir noble cause of higher education and research in thefield of Ultrasonics and allied areas carried out over last3-4 decades in Vidarbha region.

Dr. Mahavir Singh, General Secretary of USIbriefed the delegates about the activities of USI andabout the newly published USI Handbook-2015. Hereleased the handbook at the hands of Chief guests. Heannounced USI awards. Dr. T. K. Saksena MemorialAward with cash prize of Rs 5000/- for the best Ph.D.thesis in last two years, was presented to Dr. N.R. Pawarfor year 2014. Dr. S. Parthasarthi Award for best paper

publication in Journal of Pure and Applied Ultrasonics(JPAU) in 2013 was awarded to Deep Gupta and in2014 was awarded to M.H. Supriya.

Prof. Zakaria, the Chief Guest, in his address stressedthe importance of holding the symposium in theinterdisciplinary field of research and shared his expertviews on Industrial applications of ultrasonics. Dr.Kishore Ghormare expressed his views on relevance ofultrasonics in human welfare. Prof. Vikram Kumar, inhis presidential remarks appreciated the success ofsymposium due to its proper planning and organization.He also commended excellent work done in bringingout the Handbook-2015. He thanked Shri G K Arora forthe meticulous work done in this regard. Chairman ISU-2015 Prof. Vilas Tabhane welcomed the delegates andthanked all those involved in organization and successof the Symposium.

About 300 delegates from all over India and abroadattended and presented their work in this academicbonanza. Presentations were held in 9 parallel technicalsessions on various broad ultrasonic topics spread overthree days. The full papers were published, in peerreviewed and indexed International Journal of Scienceand Research (IJSR). In the first technical session, thekey note address was delivered by Prof. Vilas Tabhaneon "Fascination of Innovation in Ultrasonics". Duringvarious technical sessions on the three days of thesymposium, more than 20 invited talks were deliveredby experts of ultrasonics. More than 60 oral and 60poster papers were presented by the delegates on varioustopics including biomedical ultrasonics, Physicalacoustics and ultrasonic measurement techniques etc.The USI general body meeting was held after thedeliberations on the first day followed by culturalprogramme and dinner sponsored by Hon'ble Vice-Chancellor, RTMNU. The Symposium morning session,on the second day, the 23rd Jan 2015, was co-hosted byShivaji Science College, Nagpur. The afternoon andevening sessions were co-hosted by Shri M. M. ScienceCollege, Nagpur. These sessions were marked by nicearrangements and a beautiful cultural program followedby banquet dinner.

The International Symposium on Ultrasonics-2015 at

CONFERENCE REPORTInternational Symposium on Ultrasonics (ISU-2015)

(Focal Theme: Ultrasound in Biomedical and Industrial Applications)

22 - 24 January, 2015


Dr. Omprakash P. Chimankar Dr. Yudhisther Kumar YadavConvener, ISU-2015 Acoustics & Ultrasonics SectionAssociate Professor, Department of Physics, CSIR-National Physical LaboratoryR.T.M. Nagpur University Campus, Dr. K S Krishnan MargAmravati Road, Nagpur 440 033. New Delhi 110012Cell - +91 9766969894 E-mail : [email protected]: [email protected]

RTM University Nagpur was a grand success in thechairmanship of Prof. V A Tabhane and convenerDr. O P Chimankar. Prof. Abba Priev from Israel andProf. Zakharia from France expers in the field ofacoustics attended the Seminar as invitees from abroad.Dr. Zakharia presented his work on order, disorder,velocity dispersion and time frequency analysis on multi-layered periodic media. Dr. Yudhisther Kumar Yadav inhis talk stated about the primary standard facilities onultrasonic power measurement at CSIR-NPL and itsbiomedical and industrial applications. Dr. K M Swamyemphasised ultrasound for lowering BP in subjects withresistant hypertension. Prof. R.R. Yadav gave a talk aboutuse of ultrasonics in nanostructure-based NDE andcharacterisation of materials. Prof. S. Rajagopalan talkedon measurement of ultrasonic attenuation at highfrequencies as a tool to material characterisation.Dr. Devraj Singh spoke on ultrasonic applications inNDT&E for material characterisation under differentphysical conditions. The Abstract Book consisted of204 abstracts of the contributory papers along with theinvited papers. First day had 3 parallel sessions and aposter session after the Inauguration and Release of USIHand Book.

On the last day of the symposium, the valedictoryfunction was graced by Prof. Vinayak Deshpande,Hon'ble Vice Chancellor of RTM Nagpur University.Prof. Dr. S. Rajgopalan, Dr. R. R. Yadav, Dr. DevrajSingh, Dr. Yudhisther K. Yadav, Dr. Abba Priev (Israel),Dr. Vilas Tabhane, Shri Khankhoje, Dr. H. K. Daule, Dr.O. P. Chimankar and Dr. S. G. Charalwar participated inthe concluding session. Dr. Vinayak Deshpande stressedthe importance and relevance of organization ofsymposium/seminars/conferences/workshops and sharedhis experiences. He motivated the delegates to participatein such academic events. Prof. Dr. Vilas A. Tabhanehighlighted importance of ultrasonic research andexpressed his humble gratitude to his 36 Ph.D. Students,and various other personalities who helped and motivatedhim for achieving excellence in his academic carrier

and social endeavor.During the function USI sponsored Dr. M. Pancholi

awards for best oral & poster presentation wereannounced by Dr. Yudhisther K. Yadav, CSIR-NPL, NewDelhi. The recipients were Mr. Punit Kumar Dhawanfor oral and Ms. Aditi Pande for poster. The best threeoral and four poster presentations awards from ISU-2015 were also announced. The recipients were Mr.Nandkishor Padole, Ms. Hemlata Sharma & Mr. PrashantDabrase in oral presentation and Mr. A. K. Das, Ms.Sunita Hiwarkar, Dr. Nilesh Meshram and Dr. Anita R.Gandhe in poster presentations. The Young Scientistawards from ISU-2015 from men and women categorieswere announced by Dr. Devraj Singh. The recipientswere Dr. Ranjeeta Shriwas in women category and Dr.G. Nath & Dr. Giridhar Mishra in men category.

Shri. A. K. Gandhi, President, Shri. Barahate Secretaryof Nagpur Shikshan Mandal and Dr. S. G. Charalwar,Principal S.M.M.Science college; Adv. Shelke, PresidentShri Shivaji Education Society Amravati, Dr. D. K.Burghate, Principal Shivaji Science college and Dr. R.G. Atram, Director, Institute of Science, Nagpur werefelicitated by Hon'ble Vice-Chancellor for theircooperation and co-hosting the ISU-2015. The ex-Headof the department of Physics Prof. Dr. V. B. Sapre, ProfDr. S. V. Moharil and Prof. Dr. S. Rajgopalan were alsofelicitated for their contribution in development of thedepartment. Prof. Madhukar Yemde, Prof. P. B. Nandkarand Shri Chandrakant Udgikar were also felicitatedduring the function. All the Ph.D. recipient students ofProf. Vilas Tabhane, Dr. O. P. Chimankar and Dr. S. B.Kondawar were felicitated by Hon'ble Vice Chancellor.Dr. Archana Meshram was felicitated for her excellentcomparing of the Inaugural and Valedictory functionsand to make the event graceful. Finally, convener Dr. O.P. Chimankar proposed the formal vote of thanks. Hepraised the members of the organizing committee fortheir hard work to make the symposium a grand success.The organization of symposium was appreciated by oneand all.

Documents

Journal of Pure and Applied Ultrasonics · 2015-04-28 · Journal of Pure and Applied Ultrasonics Prediction of ultrasonic velocity of benzene and acyl derivatives though QSPR analysis