4-12 Sample Questions2.docx

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Dr. Saad B. H. Farid Characterization of Materials Exercises 2013 1 | / /

Sample Questions Laser and Electron Microscopy

1- What are the advantages of the Scanning Laser Microscope?

2- What makes the right side of the adjacent micrograph better?

3- Draw signals resulting from interaction of primary electron beam with

specimen in an electron microscope.

4- Draw Electron yield versus atomic number for Backscattered electronsand secondary electrons. Write a quick conclusion regarding SEM

observation.

5- Which half (Left and right) of

the following photo is observed

via Secondary electrons and

which is observed viaBackscattered electrons?

6- What is the left hand and right

hand SEM image resembles?

7- These are BSE micrographs of Pt particles on Alumina. Show the diff. between the left and right

micrograph

8- Which is better in depth of field, the Secondary electrons or the Back-scattered electrons?

9- What is the use of x-ray detection in electron microscopy?

10- What is the use of the scanning Auger microscopy?11- What is your advice to observe distribution of Cu in welded steel BSE or SE?

SEM images of Pt

particles on alumina.

The SE image (left)

shows the morphology

only, while the Pt

particles appear with

bright contrast in the

BSE image (right)




12- The following are SEM's of Fe particles in carbon. Show the difference between left and right image.

SEM images of Fe particles in carbon recorded with the secondary electron (left) and the back-scattered

(right) electron detector. The BSE image shows the Fe particles with bright contrast.

13- Apart from the material observed in the adjacent SEM

photo, what kind of phenomena it indicates?

14- These are SEM of a nylon fabric. Show the reason that the (right) micrograph is better

15- Name the types of failure shown in the following SEM micrographs:

Ductile dimple fracture Fatigue crack Intragranular ductile failure

Secondary electron micrographs

of a nylon fabric (a) Uncoatedspecimen showing image

degradation due to micro-

discharges (b) A similar

specimen after coating with 10

nm of gold in a sputter unit




16- The following SEM micrographs (Mag: 1000×) showing the surface of the casting void in the fracture surface of

an aluminum casting. Show the difference between the (left) and (right) micrographs

(Left): Scanning Electron Microscope (SEM) image of the surface of a casting void in the fracture surface of an

aluminum casting

(Right): Scanning Electron Microscope (SEM) image of a brittle fracture surface in an aluminum casting

The angular particles in the surface are silicon particles that contribute to the brittleness of the material

17- Draw diagrams showing the difference between BF and DF imaging (page 9)

18- What is better in elemental analysis accompanied with EM? EDS or WDS? State why.

19- Draw schematically the main components for SEM and STEM.

20- State the sample thinning techniques for TEM observation In Brief.

21- State three dedicated applications of TEM.

Dielectric Characterization

1- Why LCR measurements for dielectric materials below 1MHz are nothing to do with dielectric materials

properties? What is really indicates.

2- High AC tension is applied at terminals of Porcelain specimen. Explain why lower leakage current is

observed for porcelains sintered at higher temperatures.

3- Does dielectric properties are reflected for centrosymmetric material? Why?

Spectroscopy AAS, OES, AFS, AMS and ICP

1- Distinguish Schematically (instrumental arrangements) between Atomic absorption and Atomic emission

spectroscopy.

2- Distinguish Schematically (instrumental arrangements) between Atomic absorption and Atomic

florescence spectroscopy.

3- What is the main difference Atomic emission spectroscopy and ICP-OES?

4-

What are the main stages that an aerosol gets throw before observation of emission lines in ICP?5- How can the backgrounds are extracted from Atomic spectroscopy measurements.

6- Are the intensities linearly or logarithmically related to concentrations in Atomic spectroscopy?

7- Sketch example calibration curve for ICP-OES?

UV-visible spectroscopy

1- Why UV-Vis spectra are not preferred for qualitative analysis?

2- What are the factors that affect the Intensity and absorption maxima of a chromophore? (they are 5)

3- State Beer’s law and explain the extinction coefficient, which factors affecting it?

4- Explain sample requirements and principle of additivity in spectroscopy.

5- Explain Least squares method for over-determined system in spectroscopy.




6- Discuss Precision and accuracy with these photos:

7- State Beer's law indicating material's parameters and instrumental parameter.

Infrared and Raman Spectroscopy

1- State the main region of the vibrational spectroscopy. Which region is most useful?

2- Which absorption bands normally appear in IR-spectrum?

3- Name two examples for detection and distinguish of inorganic polymorphs via IR spectroscopy.

4- In brief, explain Fourier transform infrared spectroscopy.

5- State three optical materials used in the preparation of solid samples for the transmission infrared

spectroscopy.

6- In brief, discuss how qualitative FTIR analysis helps research work.

7- What are the main steps for quantitative FTIR analysis?

8- Why the internal standard is usually used with FTIR analysis of solid samples?

9- What are the properties required for the internal standard for FTIR quantitative measurements?

10- Which types of scattering that differentiate Raman from IR spectra?

11- What makes performing Raman spectroscopy easier recently?

12- What is the main difference between the detectable vibration of IR and Raman spectroscopy.

13- What's making Raman spectroscopy important as adjacent to IR?

14- State some applications of Raman spectroscopy

Thermal Analysis of Materials

1-

Sate endothermic and exothermic thermal reactions2- Define the main types of thermal analysis.

3- State some applications of monitoring melting points for materials.

4- Sketch melting point curve of a hypothetical substance.

5- State three techniques of measuring melting point for materials.

6- Sketch Schematic diagram illustrating the essential aspects of the DTA.

7- How calibration of DTA system is performed?

8- State the main uses of DTA and DDTA curves. State also their advantages.

9- Sketch illustrative DTA curve and state sample cases.

10- What are the advantages and disadvantages of DTA analysis?

11- Sketch the type of DSC systems, then, identify which is preferable and state why.

12- State main uses of DSC curve, DDSC curves.13- How calibration of DSC system is performed?

14- State main uses of TG curve, DTG curve.

15- State main applications of thermogravimetry

16- Define Thermodilatometry

17- State the parameters that affects the coefficient of expansion α

18- Sketch the linear differential transformer (LVDT)

19- Sketch Laser dilatometer. State the principle behind it.

20- How the thermo-dilatometer is calibrated?




Particle Size analysis by Laser diffraction

1- Discuss the following photo

2- Draw A scheme that illustrates the Occurrence of Different Particle Size Measures of a Powder

System

3- State (in brief) the sources of error in laser diffraction particle size analysis that are related to

sampling and specimen preparation related.

Gd Luck

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4-12 Sample Questions2.docx