JNTU IV B.Tech I Semester Supplimentary Examinations, February 2008
EXPERIMENTAL TECHNIQUES IN METALLOGRAPHY
(Metallurgy & Material Technology)
1. (a) How does etching helps to reveal the microstructure?
(b) Explain the principle of etching.
2. (a) What is the difference between normal etching and thermal etching?
(b) How the specimens are thermally etched?
(c) Give few examples for thermally etched specimens.
3. (a) Explain optical anisotropy in detail.
(b) Explain schematically how the optical anisotropy is produced by etching.
4. Explain in detail optical microscope objectives and eyepieces.
5. (a) Explain schematically the principle elements of the concentrated arc Microscope lamp.
(b) What are the functions of light collimator and cooling cell in the microscope?
Explain in detail.
6. (a) Describe the construction of electron microscope in detail.
(b) Describe the functioning of electron microscope in detail.
7. (a) Explain the mechanism of diffraction contrast schematically.
(b) How does selected area diffraction differ from the usual technique employed in electron diffraction cameras? Explain how accuracy of selected area diffraction is achieved.
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.