JNTU IV B.Tech I Semester Supplimentary Examinations, February 2008
EXPERIMENTAL TECHNIQUES IN METALLOGRAPHY
(Metallurgy & Material Technology)
1. (a) What is the importance of Microstructures?
(b) Classify various polishing techniques.
(c) Explain briefly various polishing procedures.
2. (a) Why dielectric coatings are required? Explain.
(b) How dielectric coatings are deposited under vacuum?
3. (a) Explain why the grain boundaries are attacked to greater extent than grains by etching reagent.
(b) Explain the optical properties of grains and grain boundaries before and after etching.
4. (a) What are different light sources in the optical microscopy? Explain them in detail.
(b) Explain in detail Achromatic and Apochromatic objectives.
5. What are different components of an optical microscope? Describe them in detail.
6. (a) Derive an expression for electron wavelength from de Broglie relation.
(b) What are Fresnel-half period zones? Explain them form the scattering of electrons from atoms.
7. (a) What are the uses and advantages of dark-field images?
(b) Explain the calibration techniques of electron microscopy.
8. (a) What do you mean by one sited thinning? Explain.
(b) When the samples are one side thinned? Explain.
(c) Explain the electron microscopy of one side thinned samples.