1

Research Scholar’s Day 2017

Venue: L-11, Lecture Hall Complex, IITK

Date: 14th October, 2017

Abstract Booklet

Department of Materials Science and Engineering Indian Institute of Technology Kanpur

Organizing Committee:

Dr. Gouthama, Convenor Dr. Anshu Gaur, Co-convenor

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Program Schedule

Time Title

09:00 – 09.15 Inauguration by Prof. I. Manna, Director, IIT Kanpur

09:15 – 10:45 SESSION 1: Physical Metallurgy

P1 Effect of external fields on spinodal decomposition - A phase-field study

Rupesh Chafle, S. Bhowmick and R. Mukherjee

P2

Investigation of interdiffusion and diffusional interactions in ternary β-Ti-Al-Mo alloys

Gyanendra Pratap Singh Chauhan and K. Kulkarni

P3 Interdiffusion in ternary Ti-Al-Nb β (BCC) phase

Aparna Tripathi and K. Kulkarni

P4

Size dependent phase transformation behaviour of Pb-Sb free alloy nanoparticles

Khushubo Tiwari, M. Manolata Devi and K. Biswas

P5

A geometrical parameter for the formation of disordered solid solutions in multi-component alloys

Akanksha Dwivedi, A.K. Singh and A. Subramaniam

P6

Combinatorial approach to understand the formation of equiatomic CoCuFeMnNi high entropy alloy

Saumya Ranjan Jha, Rani Agarwal, Reshma Sonkusare, Krishanu Biswas and N.P. Gurao

10:45 – 11.15 Tea Break

11:15 – 12.15 SESSION 2: Materials Processing

P7

A physical model study of two phase, gas -liquid flows in ladle shrouds and applications to industrial scale, ladle to tundish transfer operation

Prince K. Singh and D. Mazumdar

P8

A two-step method for synthesis of micron sized nanoporous A two-step method for synthesis of micron sized nanoporous silver powder and ZnO nanoparticle

Bharat Bhushan, B.S. Murty and K. Mondal

P9 Laser processing of Ni-Cr alloys

Ashish K Gupta, Sudhanshu S. Singh and I. Manna

P10

Development of agar based bioplastics by cross-linking with diisocyanates

Mezigebu Belay, Amit Kumar Sonker, Kousar Jahan, Gurunath Ramanathan and Vivek Verma

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12:15 – 13.00 SESSION 3: Electronic Materials & Devices

P11 Electronic structure of amorphous Zinc Oxy-nitride semiconductors

Juhi Srivastava, Somnath Bhowmick and Anshu Gaur

P12

Ionic conductivity and chemical stability study of B-site Ga3+ doped Na0.54Bi0.46TiO3- δ

Rahul Bhattacharyya and S. Omar

P13

Agarose based transparent substrates for versatile flexible electronics applications

Sankalp Verma and V. Verma

13:00 – 14:00 Break

14:00 – 15.00 SESSION 4: Mechanical Properties of Materials

P14

Tailoring triple junction characteristics to improve intergranular corrosion resistance in a nickel-based superalloy

Sandeep Sahu and S. Shekhar

P15

Effect of crystallographic texture on fracture behaviour of titanium in the presence of different stress tri-axiality

Vivek Kumar Sahu and N. P. Gurao

P16

In-situ study of crack initiation and propagation in a dual phase AlCoCrFeNi high entropy alloy

Ehsan Ghassemali, Reshma Sonkusare, K. Biswas and N. P. Gurao

P17 Fatigue behaviour of high entropy alloys

Fateh Bahadur Singh, K. Biswas and N. P. Guaro

15:00 – 16.00 SESSION 5: Materials: Structure & Properties

P18

Thermoresponsive Controlled Release of Paclitaxel from Poly (2-ethyl-2-oxazoline) Coated Maghemite Nanostructures for Targeted Drug Delivery

Nitesh Kumar, Suhela Tyeb, Nishat Manzar, Laxmidhar Behera, Bushra Ateeq and Vivek Verma

P19 Transient liquid phase sintering phenomena study in Cu-10%Sn system

N. G. Felege, N. P. Gurao and A. Upadhyaya

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P20

High phosphorus pig iron as sacrificial anode for cathodic protection of underground mild steel structures

Nisheeth K Prasad, Kallol Mondal and Saurabh Kundu

P21

Comparative corrosion behaviour of commercially available galvanised steels

K. Harikrishna, G.K.Mandal, S. S. Singh and Kallol Mondal

16:00 – 16.15 Tea Break

16:15 – 17.30 SESSION 6: Energy Materials

P22

Fabrication and characterization of printable Zinc/Silver oxide primary battery using polymer gel electrolyte membrane

Gaganjot and M. Katiyar

P23

Structural and optical properties of (AgxCu1-x)2ZnSnS4 thin films synthesized via solution route

Jitendra Kumar and S. Ingole

P24

Studying the role of buffer layer in perovskite solar cells having inverted device structure

Rahul Ranjan, A. Garg and Raju Kumar Gupta

P25

Temporal conductivity study on 1Nb2O5-10Sc2O3-89ZrO2 for the electrolyte application in solid oxide fuel cell

Vandana, A. Subramaniam, K. Balani and S. Omar

P26 Oxides for thermoelectric applications: A green approach

Tathagata Bhattacharya, Tanmoy Maiti and Somnath Bhowmick

17.30 Concluding Remarks

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Effect of External Fields on Spinodal Decomposition - A Phase-field study

Rupesh Chafle, Somnath Bhowmick and Rajdip Mukherjee

Department of Materials Science and Engineering, IIT Kanpur, Kanpur - 208016 There exist a large volume of theoretical and experimental work on understanding the effect

of external fields to control microstructure evolution. Magnetic field is particularly interesting

because of its ability to influence microstructure evolution of a number of technologically

important magnetic materials (e.g. Fe-Cr-Co, Al-Ni-Co alloys) which decompose by a

spinodal mechanism during their heat treatment. Some studies suggest that magnetic field can

also be used to modify the structure even after the decomposition has taken place. In this

work, a qualitative Phase-field model integrated with a micromagnetic approach is used to

study the effect of external magnetic field on spinodal decomposition. It is observed from the

simulations that the magnetic phase aligns itself in the direction of the applied magnetic field.

Similar phase-field model integrated with elastic field shows preferential elongation of

second phase parallel or perpendicular to the applied stress depending on the elastic

parameters. The combined effect of applied elastic field and magnetic field during spinodal

decomposition depends on the relative magnitudes of both these fields. Understanding of this

effect will prove helpful in tailoring the microstructure.

MSE RSD 2017 – P01

6

Investigation of Interdiffusion and Diffusional Interactions in

Ternary β-Ti-Al-Mo Alloys

Gyanendra Pratap Singh Chauhan1, Kaustubh N. Kulkarni1

1 Materials Science & Engineering, Indian Institute of Technology Kanpur, INDIA. (E-mail: pgyanend@iitk.ac.in, kkaustub@iitk.ac.in)

ABSTRACT

Ti-Al based alloys are widely used in aerospace and defence applications because of

their very good strength to weight ratio, excellent high temperature strength and oxidation

resistance. Mo in Ti-Al alloys increases the strength and modulus. As diffusional interactions

play an important role in the diffusion of components in multicomponent system, it is

essential to know the interdiffusion behaviour of various components of the system in order

to model and control the diffusion kinetics encountered during production as well as in

service at elevated temperatures. Limited literature available on diffusion in Ti-Al-Mo ternary

system covers only a small region of β-phase field.

The present work has determined interdiffusion coefficients in the wide region of β-

phase field of Ti-Al-Mo ternary system. Interdiffusion coefficients and diffusional

interactions in β-phase field were studied at 1100°C by using the diffusion couple

experiments. Terminal alloys were selected and homogenously prepared for assembling

diffusion couples including some iso-activity couples. Thermodynamic iso-activity lines

required for this were evaluated using the computational tool, “Thermocalc”. Using

Dayananda-Sohn and Boltzmann-Matano approach, the corresponding average and

composition dependent interdiffusion coefficients were evaluated.

In this presentation, the positive and negative thermodynamic interactions among Ti,

Al and Mo, its magnitude and nature of interdiffusion coefficients with varying compositions

of Mo and Al in β-phase will be discussed. The ternary diffusion interactions are manifested

in terms of zero flux planes, regions of uphill diffusion and comparable magnitudes of cross

versus main interdiffusion coefficients.

MSE RSD 2017 – P02

7

Interdiffusion in Ternary Ti-Al-Nb β (BCC) Phase

Aparna Tripathi1 and Kaustubh Kulkarni2*

1Department of Materials Science and Engineering , Indian Institute of Technology Kanpur,U.P. 208016, India

ABSTRACT:

In this study, interdiffusion coefficients have been calculated at three temperatures and

various compositions in BCC β phase of Ti-Al-Nb system. Two methods namely, Dayananda

Sohn analysis and extended Boltzmann Matano have been used to evaluate the

interdiffusivities as well to check the consistency of both the methods. Ti and Nb isoactivity

couples manifest relative maxima/minima in their profiles which indicates strong diffusional

interactions between the constituent elements. This fact is further validated by the cross terms

which are comparable in magnitude to the main terms. It can be concluded from the

coefficients that Nb is the slowest diffusion specie while Ti and Al are more or less similar in

behavior.

MSE RSD 2017 – P03

8

Size dependent Phase Transformation Behaviour of Pb-Sb Free

Alloy Nanoparticles

Khushubo Tiwari1*, M. Manolata Devi1, Krishanu Biswas1

1Department of Material Science and Engineering, Indian Institute of Technology, Kanpur 208016, India

*Email: khushubo@iitk.ac.in Abstract:

The present investigation is focused on the effect of size on the melting behaviour of Pb-Sb

alloy nanoparticles. Free alloy nanoparticles of Pb-17.5 atom % Sb have been synthesized by

solvothermal route using N, N-dimethylformamide (DMF) and sodium borohydride (NaBH4)

as solvent and reducing agent respectively at 140oC for 8h. The as-synthesized sample was

heat treated at 100oC for different time (1, 2, 4, 8, 12, 16, and 30h) under Ar atmosphere to

have different ranges of particle size. Transmission electron microscopy (TEM) was utilized

for the microstructural characterization of the resulting samples. TEM investigation along

with high angle annular dark field (HAADF) and energy dispersive spectrophotometry (EDS)

detectors reveal that each nanoparticle has two phases; (Pb) and (Sb). The size dependent

melting behaviour of alloys was studied using differential scanning calorimetry (DSC). The

detailed DSC analysis reveals that the eutectic temperature of alloy nanoparticles decreases

with decreasing particle size. In-Situ studies carried out in order to investigate the phase

transformation behaviour. The studies shown melting initiates at outer surface and melt

spread along the eutectic interfaces. A comparison of calculated data, based on the available

thermodynamic models for the prediction of size dependence of the melting point with the

experimental data has been carried out. Evaluated the surface properties as well as phase

diagrams of alloys on the basis of thermodynamics database, the findings are discussed in the

light of available literature.

Keywords: Nanoalloys, Solvothermal route, Eutectic, Melting

MSE RSD 2017 – P04

9

A Geometrical Parameter for the Formation of Disordered Solid Solutions

in Multi-component Alloys

Akanksha Dwivedia, Anil Kumar Singhb, and Anandh Subramaniama

a Department of Materials Science and Engineering, Indian Institute of Technology Kanpur, b Department of Physics, Indian Institute of Technology Kanpur, Kanpur-208016.

Abstract

One or more disordered solid solutions (DSS) are entropically stabilized in high entropy

alloys (HEA), in competition with possible intermetallic compounds or phase segregation. In

spite of the supreme role of Gibbs free energy, various parameters have been used to

understand the formation of DSS in multi-component alloys. These include, the -parameter

(based on atomic size differences between the elements), the enthalpy of mixing (Hmix) the

-parameter (TmSmix/|Hmix|). These parameters have had different degrees of success in the

context of understanding the formation of DSS in multi-component alloys. In the current

work, we develop a purely geometrical parameter ( = Smix/2) to predict the formation of

DSS. Ranges are prescribed for this parameter for the formation of: (a) DSS, (b) a mixture

involving compounds and (c) (only) compound(s). Results from the literature are used to

highlight the utility of the -parameter, in the context of other standard approaches. The role

of the value of the -parameter in understanding the nature (complexity) and volume fraction

of the compound formed is also highlighted.

MSE RSD 2017 – P05

10

Combinatorial approach to understand the formation of equiatomic

CoCuFeMnNi high entropy alloy

Saumya Ranjan Jha1, 2, Rani Agarwal2, Reshma Sonkusare2, Krishanu Biswas2, N.P. Gurao2

1Department of Metallurgical and Materials Engineering, NIT Durgapur

2Department of Materials Science and Engineering, IIT Kanpur

Multi principal multi component high entropy alloys (HEAs) are studied widely due to their

promising properties such as high strength, corrosion resistance, hardness and high

temperature stability. Studies have shown the procedure to identify single phase HEAs using

thermodynamic modelling and a single phase face centered cubic CoCuFeMnNi HEA was

recently identified using the CALculation of PHAse Diagrams (CALPHAD) approach. The

present investigation aims to understand the formation of equiatomic CoCuFeMnNi HEA

through synthesis and mechanical testing of equiatomic binary, ternary and quaternary

subsets of the quinary alloy. Single phase Fe-Mn, Fe-Mn-Ni, and Fe-Mn-Ni-Co subsets as

obtained from thermodynamic modelling using Thermocalc software based on CALPHAD

were melted using vacuum arc melting and suction casting techniques and were subsequently

homogenized and deformed to 90% reduction. After the deformation, alloys were

recrystallized and were further used for the mechanical testing along with microstructural and

micro-textural characterization using scanning electron microscopy and electron backscatter

diffraction (EBSD). EBSD analysis revealed that the deformation in these alloy subsets is slip

dominated like the quinary alloy. A comparative and systematic study of the trends of this

single phase face-center cubic quinary alloy reveals that the increase in configurational

entropy of mixing doesn’t necessarily contribute to the improvement in mechanical

properties. The basic philosophy of alloying to achieve improvement in strength and ductility

in high entropy alloys is discussed in the light of experimental results.

MSE RSD 2017 – P06

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A physical model study of two phase, gas-liquid slows in ladle shrouds and

applications to industrial scale, ladle to tundish transfer operation

Prince K. Singh and Dipak Mazumdar Department of Materials Science and Engineering Indian Institute of Technology, Kanpur, INDIA

Abstract

Physical modelling of two phase , argon- molten steel flows inside a ladle shroud during ladle

to tundish transfer of liquid steel has been carried out. Full scale, geometrically and

dynamically similar Perspex models of both bloom and slab casting shrouds has been

employed. Operating conditions during the experiments are close to the actual industrial

practices. Depending on the volume of argon injection rate relative to metal flow, markedly

different flow regimes inside the shroud can result while the later is submerged.

Experimental observations have clearly indicated that at relatively high gas flow rate relative

to liquid flow, concentric, gas- liquid annular flow can occur and prevails over the entire

height of the shroud. In contrast, close to zero gas flow rate, a shroud tends to be practically

completely filled with the liquid and a near homogeneous (with few dispersed bubbles in the

flowing liquid column) flow conditions prevail within. Between the extremities, a mixed

scenario develops, in which, annular, co-axial gas-liquid flow is observed in the upper part

while an intensely mixed, gas- liquid, two phase column flow in the lower portion of the

shroud. The line of demarcation between the upper annular and lower two phase flow

regions (termed as the mixed flow meniscus and denoted by Hm ), measured from the flow

inlet nozzle, can be adequately described via the following dimensionless correlations ( in Si

unit):

27.0

5

229.519.1

321

s

l

s

c

l

g

s

m

gD

Q

D

D

Q

Q

D

H

In the above , Hm (m) is the mixed flow meniscus height (measured from the liquid inlet)

inside the shroud, Ds (m) and Dc (m) are respectively the shroud and collector nozzle

diameters, Qg (m3/s) is the shrouding gas flow rate and Ql (m3/s) is the liquid throughput rate.

MSE RSD 2017 – P07

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A two-step method for synthesis of micron sized nanoporous

silver powder and ZnO nanoparticles

B. Bhushan1, B.S. Murty2 and K. Mondal1

1Department of Materials Science and Engineering,

Indian Institute of Technology, Kanpur 208016, India

2Department of Metallurgical and Materials Engineering

Indian Institute of Technology Madras, Chennai 600036, India

Abstract:

Micron-sized nanoporous silver powder with pore size of ~100-160 nm and specific surface

area of ~4.7-5.5 m2/g was synthesized from three mechanically alloyed Ag-Zn powders (composition:

25, 50 and 75 at% Zn). Dealloying was carried out at free corrosion (without using any external

current or potential) conditions in NaOH, HCl and AgNO3 solutions. Both partial and complete

dealloying were obtained by suitable choice of electrolyte and time of exposure. In addition to this, Zn

in the solution after dealloying was recovered in the form of ZnO nanoparticles with particle size of

56±18 nm. The effect of composition and electrolyte on the degree of dealloying was also studied.

 

MSE RSD 2017 – P08

13

Laser Processing of Ni-Cr alloys

Ashish Kumar Gupta, Sudhanshu S. Singh and I. Manna Department of Materials Science and Engineering,

Indian Institute of Technology Kanpur, Kanpur, Uttar Pradesh, 208016, India

Abstract

In recent years, Direct Metal Deposition (DMD) has emerged as an excellent manufacturing

technique compared to other conventional techniques such as Casting and Powder

metallurgy. It enables the direct production of high performance metal components from

metal powders. In DMD process, the powder is fed into the focal point of laser, over the

substrate, where it is melted and solidified to form a layer. The solidification rate in the laser

processing can reach to a level of 103-106 ◦C/s. This results in the formation of non-

equilibrium phases which would not be possible from conventional casting technique.

Moreover, the mechanical properties of the components fabricated through this route have

been found to be superior to their counterpart cast and wrought alloys due to formation of

much finer grains (due to fast cooling).

In this talk, the microstructural characterization and mechanical properties of a series

of laser fabricated Ni-Cr alloys are presented. Five different samples (100Ni, 80Ni-20Cr,

50Ni-50Cr, 79Cr-21Ni and 100Cr) were prepared using a 6 kW fiber coupled diode laser

system having a spot size of 3 mm diameter. A co-axial powder feeding nozzle assembly was

used to feed the powder co-axially with the laser beam. To obtain clads, laser scanning

velocity and power were chosen as 4 mm/s and 400 W, respectively. Microstructural

characterization and mechanical properties evaluation were done using optical microscopy,

SEM, XRD and hardness measurement.

Keywords: Direct Metal Deposition (DMD), Microstructure, Mechanical Properties

MSE RSD 2017 – P09

14

Development of agar based bioplastics by cross-linking with diisocyanates

Mezigebu Belay1,*, Amit Kumar Sonker1, Kousar Jahan1,

Gurunath Ramanathan2, Vivek Verma1,3

1Department of Materials Science and Engineering, Indian Institute of Technology Kanpur,

2Department of Chemistry, Indian Institute of Technology Kanpur,

3Centre of Environmental Science and Engineering, Indian Institute of Technology Kanpur,

*: Presenting author

Abstract

Our heavy dependence on petro-plastics is posing serious environmental concerns due to their

limited service life and non- biodegradability. Biodegradable plastics are environmental

friendly alternative to petro-plastics. Agar, a natural bioplastic, has shown potential in

packaging and biomedical applications. However, its moderate strength and poor water

resistance leave us wanting for more. To overcome the above lacunae, we have chemically

cross linked agar using two kinds of diisocyanates namely 4, 4 diphenyl diisocyanate (DDI)

and 1, 6 hexamethylene diisocyanate (HDI). The formation of carbamate cross-link network

in the cross-linked agar was confirmed by FTIR spectra. The aromatic diisocyanate (DDI)

showed better properties than its aliphatic counterpart (HDI), which could be due to its higher

reactivity. Crosslinking resulted in reduction of water absorption from 206% for pure agar to

a minimum of 33.6% and 43.6% for DDI and HDI cross linked samples, respectively. The

maximum tensile strength was observed for DDI cross-linked agar (45.3 MPa) which was

higher than HDI cross-linked agar (30.6 MPa) and agar (31.7 MPa). The thermal stability of

cross linked samples was also improved.

MSE RSD 2017 – P10

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Electronic structure of amorphous Zinc Oxy-nitride semiconductors

Juhi Srivastava, Somnath Bhowmick and Anshu Gaur

Department of Material Science and Engineering, Indian Institute of Technology Kanpur

(Email: juhisri@iitk.ac.in, bsomnath@iitk.ac.in, agaur@iitk.ac.in)

ABSTRACT In the case of poly-crystalline single metal oxide semiconductors, such as ZnO, In2O3, Ga2O3 and

SnO2, the electronic transport is limited due to presence of potential barrier created at the grain

boundaries. Electronic transport in oxide semiconductors can be improved by using amorphous phases

of these oxides. One of the ways the amorphous oxide semiconductors can be obtained is by mixing

single metal oxides which have different crystal structures. One of such multi-cation oxide

semiconductor is a-IGZO, which shows good electronic transport properties even in amorphous

phase. However, the interaction between different metal s-orbitals, which form the electron

conduction path, may limit the electron mobility due to the potential barrier for electron transfer

between overlapping s-orbitals of different metal cations.

Another way of forming amorphous semiconductors is by using multi-anion approach rather

than multi-cation approach as in a-IGZO. One of the candidate for this approach is a-ZnON which has

been gaining more attention recently and has shown to have better carrier transport properties

compared to a-IGZO. In this work, we have studied the electronic structure for two compositions of a-

ZnON, i.e. O:N=2:1 and O:N=1:1 and compared the behaviour with electronic structure of a-IGZO.

MSE RSD 2017 – P11

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Ionic Conductivity and Chemical Stability Study of B-site Ga3+ Doped

Na0.54Bi0.46TiO3- δ

Rahul Bhattacharyya and Shobit Omar

Department of Materials Science and Engineering, Indian Institute of

Technology, Kanpur, Uttar Pradesh, India 208016

brahul@iitk.ac.in, somar@iitk.ac.in

Abstract

Due to the unusual electrical properties and potential ability to replace lead zirconia

titanate (PZT), sodium bismuth titanate (NBT) has drawn immense interest now a days. It

exhibits high oxide-ion conductivity comparable with Gd0.10Ce0.90O2-δ (GDC), a state-of-art

material. It undergoes phase transitions from cubic to tetragonal and tetragonal to

rhombohedral on cooling below 540-500°C and 400-255°C, respectively. Non-stoichiometric

NBT compositions with Na/Bi molar ratio >1 exhibit at least three orders of magnitude

higher conductivity than that of compositions having molar ratio <1. Recent computational

work has predicted that A-site substitution in NBT can render better conductivity than B-site

doping due to less binding energy barrier. Na addition in place of Bi has improved the ionic

conductivity at a reasonable amount. In search of further improvement, Ga3+ may be

considered as a potential B-site dopant on the basis of ionic size, polarizability, and bond

strength with oxygen. In the present work, we investigated the influence of Ga3+ doping in

Na-excess NBT on the phase stability and ionic conductivity. Polycrystalline dense samples

of Na0.54Bi0.46Ti1-xGaxO3- δ (x = 0, 1) were prepared via solid-state reaction method. XRD

revealed a single perovskite rhombohedral phase at room temperature. 1 mol. % Ga3+ doping

has exhibited a grain conductivity of 7.1 mS.cm-1 at 600oC. Annealing treatment of

Na0.54Bi0.46T0.99Ga0.01O3- δ under reducing atmosphere at 600oC suggested chemically

stability of the composition at ≤550 oC. The pO2-independent conductivity suggested that the

conduction behavior is predominantly ionic in nature. The conductivity results and the ageing

behavior of Na0.54Bi0.46T0.99Ga0.01O3- δ at 600oC in air and reducing conditions will be

presented.

MSE RSD 2017 – P12

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Agarose based transparent substrates for versatile flexible electronics applications

Sankalp Verma and Vivek Verma

Department of Materials Science and Engineering,

IIT Kanpur, Kanpur - 208016

Abstract:

The growing flexible electronics sector requires substrates that should not only allow

excellent conformability but should also withstand various micro-fabrication processes.

Lithography, among the micro-fabrication processes currently being used, is still a major

electronics fabrication tool. Hence for a wider applicability, it is a desired that the flexible

substrates be lithography processable. Furthermore, for a sustainable future, we also want the

flexible devices to disintegrate into environmentally benign products, once the intended life is

over. Therefore, in this work, we demonstrate agarose based transparent, biodegradable,

flexible and lithography processable substrates that show remarkable optical and thermal

properties. The developed substrate is compatible not only to UV lithography but also to

screen/stencil printing using water based inks. As a proof of concept, we develop aluminium

and antibody patterns of varying shapes and sizes on the prepared substrates.

MSE RSD 2017 – P13

18

Tailoring triple junction characteristics to improve intergranular corrosion

resistance in a nickel-based superalloy

Sandeep Sahu and Shashank Shekhar

WL-304, Western Lab, Department of Materials Science and Engineering, Indian Institute of Technology Kanpur, Kanpur-208016, India

ABSTRACT

Twinning related ‘grain boundary engineering’ is a well-established technique to improve functional

and mechanical properties in low stacking fault energy face centred cubic (FCC) materials. Though,

modifications in the grain boundary character distribution is necessary, it is not a sufficient criterion

to improve intergranular characteristics. Grain boundaries related properties depend on the spatial

distribution of various kinds of triple junctions. In this aspect, the current work focuses on increasing

the J2 (2 coincidence site lattice, CSL boundaries at the triple junctions) and J3 type of triple junctions

and decreasing J0 and J1 types of triple junctions. For it, low strain, (4-24%) was imparted to Inconel

600 alloy by hot rolling in order to minimize the generation of highly deviated twins. Deformed

material was given a short annealing treatment of 10 minutes to control grain growth. The results

showed an increment in total CSL fraction (3≤Σ≤29) as high as 77% having a dominant fraction from

twin (Σ3) boundaries (64%). The distribution of all the kinds of triple junctions was examined. All the

samples were tested for intergranular corrosion resistance using immersion corrosion test as per G-28

standard. The samples having high fraction of J2 and J3 types of triple junctions were found to have

much less corrosion in comparison to samples having high fraction of J0 and J1 types of triple

junctions.

MSE RSD 2017 – P14

19

Effect of crystallographic texture on fracture behaviour of titanium in the

presence of different stress tri-axiality

Vivek Kumar Sahu*, Nilesh Prakash Gurao

Department of Materials Science and Engineering, Indian Institute of Technology Kanpur,

Kanpur-208016, India

*Corresponding author: vsahu@iitk.ac.in

Titanium and its alloys that have high specific strength, good ductility, excellent

biocompatibility and corrosion resistance are useful for structural applications in marine,

aerospace and bio-medical industry. Hexagonal close pack titanium with less than ideal c/a

ratio (1.588) accommodates plastic deformation primarily by the operation of prismatic <a>

as well as basal, pyramidal <c+a> slip systems accompanied with extension twinning and

contraction twinning to provide five independent slip systems according to Von Mises

criterion. Deformation behavior of titanium has been studied in different modes of

deformation like tension, compression, plane strain deformation (rolling and shear) over a

range of temperature. Strain rate and micro-mechanisms of deformation in titanium are well

established. However, the effect of crystallographic texture on the fracture behaviour of

titanium in the presence of different stress tri-axiality introduced by presence of notches of

different geometry is still unexplored. In the present investigation, flat specimens with a

double U and V notch were obtained from rolled and annealed block of commercially pure

titanium from ND and RD plane (sample A and B respectively). The detailed micro-textural

analysis was carried out using electron back scatter diffraction. It was observed that sample A

with initial prismatic-texture shows higher strain to failure compared to sample B for U and

V notch specimen. The V-notch specimen shows lower elongation compared to the U-notch

specimen for both the orientation. Fractography of the fractured samples indicate mixed

mode fracture with sample B showing more brittle behaviour than sample A and V-notch

sample being more brittle than U-notch sample. The interaction of initial texture and stress

tri-axiality caused by the presence of notch in deciding the micro-mechanisms of deformation

and failure will be discussed in details.

MSE RSD 2017 – P15

20

In-situ study of crack initiation and propogation in a dual phase

AlCoCrFeNi high entropy alloy

Ehsan Ghassemali1, Reshma Sonkusare2, Krishanu Biswas2, N. P. Gurao2

1 School of Engineering, Jonkoping University, Sweden

2 Indian Institute of Technology Kanpur, India

This study reports the effect of phase distribution on crack propagation in a dual phase AlCoCrFeNi

high entropy alloy (HEA) under tensile loading. The alloy is characterized by the presence of a brittle

disordered BCC phase that can be toughened by precipitation of a ductile FCC phase during

homogenization heat treatment. The stress and strain partitioning between the two phases is of

paramount importance to determine the mechanical response of this alloy. The as-cast alloy was

subjected to homogenization at 1273 K for 6 h to prevent the formation of detrimental sigma phases

and to precipitate the ductile FCC phase. In-situ tensile test in a scanning electron microscope with an

electron backscatter diffraction facility was carried out to understand the micro-mechanisms of

deformation of the alloy. Precipitation of the FCC phase at the BCC grain boundaries reflected the

effect of the FCC phase on crack deflection and branching during propagation. The strain partitioning

between the two phases and the evolution of misorientation distribution was investigated. It is

observed that the presence of ductile FCC high entropy phase can impart good room temperature

ductility to the brittle BCC phase. As there are very few investigations performed on the dual phase

HEAs, a proper microstructural design can be be achieved and can be utilized to toughen the brittle

HEAs.

MSE RSD 2017 – P16

21

Fatigue Behaviour of High Entropy Alloys

Fateh Bahadur

Department of Materials Science and Engineering, Indian Institute of Technology Kanpur, Kanpur - 208016

Supervisors: Dr. Krishanu Biswas and Dr. Nilesh Prakash Gurao

Abstract

High Entropy Alloys (HEAs) are equi-atomic or near equi-atomic, multiple element systems

which gets crystallised as a single phase or multi-phase solid containing different crystal

structures. The validation for HEA is that its high configurational entropy contributes to the

total free energy in the alloy, with five or more major elements which helps to stabilize the

solid-solution relative to multiphase microstructures. The solid solution of BCC and FCC

phases are reported to possess various properties, i.e., excellent room temperature

compressive mechanical property, higher yield stress, fracture strength and plastic strain.

These excellent mechanical properties provide scope for study of fatigue behavior of HEAs.

The fatigue behavior and lifetime prediction are necessary for structural applications,

particularly, for aerospace applications. . The study of fatigue resistance associated with

HEAs at high stresses has been reported to have prolonged fatigue life and superior fatigue

behaviour compared to other conventional alloys. The FCC based HEA is shown to have

better fatigue resistance than BCC HEA. But, there is urgent need to explore mechanisms of

leading to fatigue resistance and to develop life prediction models.

MSE RSD 2017 – P17

22

Thermoresponsive Controlled Release of Paclitaxel from Poly (2-ethyl-2-

oxazoline) Coated Maghemite Nanostructures for Targeted Drug Delivery

Nitesh Kumar1, Suhela Tyeb2, Nishat Manzar2, Laxmidhar Behera3, Bushra Ateeq2, Vivek Verma1,4*

1Materials Science and Engineering, Indian Institute of Technology Kanpur, Kanpur, India 2Biological Sciences and Bioengineering, Indian Institute of Technology Kanpur, Kanpur,

India 3Electrical Engineering, Indian Institute of Technology Kanpur, Kanpur, India

4Centre for Environmental Science & Engineering, Indian Institute of Technology Kanpur, Kanpur, India

Abstract:

Maghemite (γ - Fe2O3) based nanostructures are reported to exhibit several applications in

areas of targeted therapy and diagnosis. These nanostructures consist of a spherical polymer

shell which acts as a drug carrying reservoir and a maghemite core which facilitates their

active magnetic targeting to the desired location in the body. However, the major drawbacks

with this type of morphology is a higher drag force and lower net magnetic moments of the

individual nanostructures navigating inside the blood stream. This leads to a larger amount of

magnetic motive force required to steer these nanostructures through blood stream. In the

current work, a novel linear core shell maghemite nanostructure with a lower drag coefficient

and enhanced net magnetic moment was developed for potential application in targeted

cancer therapy. These nanostructures were further loaded by a polar anticancer drug

paclitaxel for treatment of prostate cancer cells cultured in vitro. The targeted release of drug

to the cancer cells was performed via a thermoresponsive mechanism at 41°C.

MSE RSD 2017 – P18

23

Transient liquid phase sintering phenomena study in Cu-10%Sn

system

N.G. Felege1, N. P. Gurao2, Anish Upadhyaya3

Department of Materials Science & Engineering Indian Institute of Technology, Kanpur, 208016, India

Abstract

Cu-Sn system have been produced in powder metallurgy mainly for production of

Porous self-lubricating bearings. Many researchers intensively studied the sintering

mechanism in the copper-tin system using different methods such as: Hot stage

photomicrography, Dilatometer method, and DTA analysis. Their findings lead to two

main school of thoughts. The first believes that copper diffuses into tin to from

various intermetallic which either decompose or get transformed into less-tin-rich

phases as the sintering progresses. The second is that tin melts, spreads and diffuses

into copper, leaving behind secondary pores of approximately the same size and

shape. As a result, no strong conclusive description of the transient liquid phase

sintering phenomenon in Cu-10%Sn. The present work attempts to study the sintering

mechanism in Cu-10%Sn system by in situ heating method and chemical assisted

EBSD. In situ SEM micrographs and EDS line scans and EDS maps at 200°C,

250°C, 300°C, and 350°C are used to understand how the concentration and

microstructure changes in real time heating. The EDS maps and concentration profiles

of line scan indicated that Tin melts at 232°C and spreads around the copper particle

and thereby producing tin pool with further heating it diffuses in to copper particles as

a result porosity develops at center of the pool and continuously grows until the entire

tin diffuses in to the copper particles. Copper also interacts with Tin and form

intermetallic compounds.

MSE RSD 2017 – P19

24

High Phosphorus Pig Iron as Sacrificial Anode for

Cathodic Protection of Underground Mild Steel Structures

Nisheeth Kumar Prasad, Dr. Kallol Mondal Materials Science and Engineering Department

Indian Institute of Technology Kanpur, UP, India - 208016

Dr. Saurabh Kundu Research & Development and Scientific Services

Tata Steel Limited, Jamshedpur, Jharkhand, India - 831001

Abstract

Cathodic protection is an effective method for the corrosion protection of underground and

undersea metallic structures. Magnesium, zinc and aluminium based alloys are the commonly

used sacrificial anodes for cathodic protection of steel structures. High phosphorus

archaeological irons are known to possess excellent corrosion resistance under atmospheric

exposure condition due to presence of ionic phosphate on the outer surface of iron which

results in the formation of a protective passive film. However, under completely immersed

condition, the protective passive film becomes unstable and results in continuous dissolution

of the outer rust layer. Presence of high phosphorus in the archaeological iron has been found

to accelerate the corrosion rate under immersed condition. In the present work, pig iron with

high phosphorus content was utilized as sacrificial anode for cathodic protection of

underground mild steel plates and the results were compared with that of a commercially pure

magnesium sacrificial anode. Driving potential between the galvanically coupled sacrificial

anodes and mild steel plates were continuously monitored in real time for one month

duration. Based on theopen circuit potential (OCP) in 3.5 wt% NaCl solution, pig iron was

found to be more anodic as compared to the mild steel. Microstructure and morphology of the

corrosion products formed on the surface of pig iron, magnesium and mild steel plates were

observed with the help of optical microscope and scanning electron microscope. Phase

identification were performed using X-ray diffraction, Raman spectroscopy and Fourier

transform infrared spectroscopy.Formation of soluble iron phosphate hydrate (FePO4.2H2O),

presence of non-metallic inclusions and shallow pits on the surface of pig iron under buried

condition were critical from the point of sacrificial effect, indicating the possible scientific

reasons for high phosphorous pig iron to be used as cost effective sacrificial anode.

MSE RSD 2017 – P20

25

Comparative Corrosion Behaviour of Commercially Available

Galvanised Steels

K.Hari Krishna1, G.K.Mandal2, S. S. Singh1 and K.Mondal1

1 Department of Material Science and Engineering, Indian Institute of Technology, Kanpur-208016, India

2 CSIR-National Metallurgical Laboratory, Jamshedpur, Jharkhand, India

Abstract

Galvanised or Zn coated steel provides corrosion protection to underlying steel due to

sacrificial effect of Zn, where Zn dissolves and Fe acts a cathodic part in the electrochemical

reactions. Galvanised steels are used in constructions (rebar), beams, etc., piping industries,

automobile industries, roof covers, etc.

The present study deals with the comparative corrosion behaviour of the commercially

available galvanised steel sheets in Indian market. The galvanised sheets were tested by

potentiodynamic polarisation, linear polarisation, and impedance spectroscopy in freely

aerated 3.5% NaCl solution. In addition, electrochemical polarisation behaviour of the

underlying steel substrates (after removal of the galvanised layer) was also tested. The phase

analysis of the corrosion products was characterised by using Raman spectroscopy and X-ray

diffraction (XRD) technique. The morphology of the corroded samples was also analysed

with the help of scanning electron microscope (SEM). The effective sacrificial behaviour of

the galvanised layer was compared for the different steel sheets as a function of the layer

thickness, composition and morphology. Moreover, steel composition also played important

variable to decide the effective sacrificial behaviour of the galvanised layer.

MSE RSD 2017 – P21

26

Fabrication and characterization of printable Zinc/Silver Oxide primary

battery using polymer gel electrolyte membrane

Gaganjot a, b, *and Monica Katiyar a, b

a Department of Materials Science & Engineering, Indian Institute of Technology, Kanpur, U.P. – 208016, India

b National Centre for Flexible Electronics, Indian Institute Technology, Kanpur, U.P. – 208016, India

* Correspondence: gaganjot@iitk.ac.in

Abstract

Printable batteries have attracted great attention as an emerging power source for wearable

electronics such as RFID tags, implantable medical devices etc. Devices such as digital

cameras, mobile phones and notebooks use Li-ion based batteries. However, the need for

environmental friendly batteries with high energy density has led to the development of

partially printed primary zinc-silver oxide batteries. It has been reported that printed Zn/Ag2O

systems have low cost, light weight and easy processing methods. In this paper, we will

present the results of thin film batteries fabricated using printing techniques. In earlier works,

methyl cellulose and polyvinyl alcohol had been used as the binding material for the Zn and

Ag2O electrode inks. For our work water-based printable inks have been formulated for

fabricating battery electrodes. The electrodes have been prepared using zinc (un-doped) and

silver oxide micro-powders. Silver has been used as the current collectors printed at the top of

the PET substrate. The electrodes have been sandwiched together with a solid polymer

electrolyte membrane to obtain stacked battery. The polymer based electrolyte membrane has

been prepared using poly (acrylic acid) (PAA) as a host for the active electrolyte potassium

hydroxide (KOH). Different molar concentrations of electrolyte have been studied. The

current collectors have been characterized for conductivity by 4-probe measurement

technique and the solid electrolyte membrane by impedance spectroscopy. The complete

batteries have been characterized for discharge characteristics at different discharge rates.

LCD powered by the battery has been demonstrated under un-flexed and flexed conditions as

a proof of the concept.

MSE RSD 2017 – P22

27

Structural and optical properties of (AgxCu1-x)2ZnSnS4 thin films

synthesised via solution route

Jitendra Kumar and Sarang Ingole

Laboratory of Photovoltaic and Energy Storage Materials Department of Materials Science & Engineering

Indian Institute of Technology Kanpur, Kanpur 208016 (INDIA) Email: jiten@iitk.ac.in

Abstract

Silver (Ag) has been introduced in the quaternary compound Cu2ZnSnS4 synthesized via

solution chemistry. Thin films of the resulting pentanary alloys (AgxCu1-x)2ZnSnS4 (0 ≤ x ≤

1) show remarkable change in their microstructure and electronic properties with the

increasing Ag content. Going from Cu2ZnSnS4 (x = 0) to Ag2ZnSnS4 (x = 1), the grain size

increased from 0.13 to 2 µm which could be attributed to the liquid assisted grain growth

mechanism. The optical band gap increased from 1.5 to 2.0 eV due to the influence of d-

orbitals of Ag atoms on the valence band edge. The charge carrier density decreased by two

orders of magnitude with only 4 atomic % Ag (x = 0.04) incorporated in the films, which can

be attributed to the reduction in the density of CuZn and VCu point defects with Ag atoms

occupying the Cu-sublattice sites. Also, with increasing Ag content the lattice parameters a

and b increased from 5.42 to 5.82 Å, whereas there was negligible change in the lattice

parameter c.

MSE RSD 2017 – P23

28

Studying the role of buffer layer in perovskite solar cells having inverted

device structure

Rahul Ranjan1, Ashish Garg2 and Raju Kumar Gupta*1

1Department of Chemical Engineering, Indian Institute of Technology Kanpur, Kanpur-208016, UP, India

2Department of Materials Science and Engineering, Indian Institute of Technology Kanpur, Kanpur-208016, UP, India

Abstract

Soaring electricity requirement of India as well as the world along and associated environmental effects due to use of fossil fuels have motivated researchers to explore alternate sources of producing electricity. Among various options, solar photovoltaic technologies, which convert sun light directly into electricity, are well poised to meet the challenge. Whilst recent times have seen surge in PV installations due to decreasing cost of Si, it would desirable to produce thin film solar cells which not only reduce the material consumption and thus reduce the costs but also make solar PV panels significantly lighter and make their handing and transportation a lot easier. Among various thin film technologies, perovskite solar cells (PSCs) have emerged as serious contenders due to potentially low fabrication cost due to solution processability of the device and potential for high efficiency. The cell efficiencies have risen from less than 4% in 2009 to a certified 22.1% in recent times. Such a high photovoltaic performance is attributed to high optical absorption characteristics and long diffusion lengths of excitons in perovskites, further augmented by engineering their microstructural characteristics. Having demonstrated high efficiencies, there is a growing need to replace some of the materials in conventional device structure due to high cost and stability issues such as Spiro-OMeTAD. However, these replacements are not often associated with significant drop in the efficiency. This work reports focuses on the development of perovskite solar cells using the inverted device structure (ITO/PEDOT:PSS/Perovskite/PCBM /Al) with the use of simple materials which could be potential useful in lowering the cost of PSCs. The use of buffer layer of PEDOT:PSS plays an important role in hole transportation and perovskite film formation. The optimization of processing conditions of PEDOT:PSS films led to device efficiency of ~6% with further improvements expected.

MSE RSD 2017 – P24

29

Temporal Conductivity Study on 1Nb2O5-10Sc2O3-89ZrO2 for the

Electrolyte Application in Solid Oxide Fuel Cell

Vandana, Anandh Subramaniam, Kantesh Balani and Shobit Omar*

Department of Materials Science and Engineering,

Indian Institute of Technology Kanpur, Kanpur Uttar Pradesh, India, 208016

Abstract

Scandia stabilized zirconia (ScSZ) electrolyte offers a benefit of lowering the high operating

temperature (~1000oC) of solid oxide fuel cells to the intermediate temperature range (500-

700°C). In 11Sc2O3-89ZrO2 (11ScSZ) system, below 600 °C, cubic phase partially transforms

to lower conducting rhombohedral β-phase caused by the long range oxygen vacancy

ordering. Substitution of 1 mol.% Nb2O5 for Sc2O3 in 11ScSZ leads to a complete cubic phase

stabilization at room temperature which as a result a significant conductivity enhancement.

The present work highlight the influence of ageing on the phase stability and conductivity of

1Nb2O5-10Sc2O3-89ZrO2 (1Nb10ScSZ) for the electrolyte application in SOFCs. Impedance

spectroscopy was used to perform in-situ conductivity measurement on the polycrystalline

sample over the frequency range of 32 MHz-0.1Hz at 650ºC for 2000 h in air. A considerable

29% of conductivity loss was observed during the first 1000 h; thereafter conductivity

remained relatively stable. Impedance analysis revealed that the major contribution to the

conductivity degradation arises from the increase in intra-grain resistivity. Microstructural

analysis performed using XRD, TEM and Raman spectroscopy indicated that both the unaged

and aged 1Nb10ScSZ samples consisted of metastable t//-phase. However, the extent of

tetragonality was found to increase after ageing. The formation of low-symmetry phase was

suggested to be the reason for the grain conductivity loss in 1Nb10ScSZ. After 2000 h of

ageing, total conductivity degraded from 19.36 mS.cm-1 to 13.8 mS.cm-1 at 650°C, which is

>30% higher than the desired 10 mS.cm-1 required for the electrolyte at operating

temperature.

MSE RSD 2017 – P25

30

Oxides for Thermoelectric Applications: A Green Approach

Tathagata Bhattacharya, T Maiti and S Bhowmick

Department of Materials Science and Engineering, Indian Institute of Technology Kanpur, Kanpur - 208016

Abstract

The prospects of Double Perovskite (DP) and Perovskite based materials as candidates for

high temperature thermoelectric materials were investigated. Among the various complex

perovskites, SrTiO3 based oxides had shown great potential for thermoelectric applications.

Sr2TiMO6 (M = Fe, Co) based DPs were synthesized by Roy et al., [1] using conventional

solid state route. The oxide samples were investigated for their crystal structure and

morphology by XRD and SEM, respectively. In another report by Saxena et al. [2],

Sr2TiMoO6 DP was investigated as a potential candidate for thermoelectric application,

where the researchers had adopted the same methodology that was followed by Roy et al., to

synthesize and characterize their material. In another study by Roy et al., [3], the influence of

Spark Plasma Sintering (SPS) over Conventional Sintering was investigated on Nb-doped

SrTiO3 perovskite. Also, the operating parameters for SPS were optimized to obtain the best

thermoelectric performance from the material.

References:

[1] P. Roy et. al., Integrated Ferroelectrics, 2016, Vol. 174, 34–42.

[2] M. Saxena et. al., Scripta Materialia, 2017, Vol. 130, 205–209.

[3] P. Roy et. al., Ceramics International, 2017, Vol. 43, 12809–12813.

MSE RSD 2017 – P26