II B.Tech I Semester Supplimentary Examinations, February 2008
(Metallurgy & Material Technology)
1. Give an account on the following:
(a) Condenser system
(b) Light filters
(c) Objective lens
2. (a) Define and explain space lattice, unit cell and crystal. How are they related?
(b) Explain why there are more metallic elements than non metallic elements in the periodic table.
(c) What is stacking sequence? Explain stacking sequences for FCC and BCC structures.
3. (a) What is a solid solution? Give the classification and explain the rules for the formation of solid solutions.
(b) Explain why atomic size difference is only 4.2% still Zn can dissolve up to 38.4% in Cu?
4. (a) Assuming a spherical nucleus and negligible strain effects, calculate the critical radius of nuclei for homogeneous nucleation.
(b) Determine the effect of temperature and time on nucleation rate.
5. (a) Discuss in detail order-disorder transformations with neat sketches.
(b) Explain the effects of alloying elements on steels.
6. (a) What are α brasses. What are various types of α – brasses. Mention their properties and applications.
(b) Explain the following with respect to composition, properties, microstructure and applications
i. Muntz metal
ii. Cartridge brass.
7. (a) What are quench cracks? Explain the possible reasons for their formation? How to avoid their formation
(b) Distinguish between ‘retained austenite’ and stabilized austenite.
8. What do you mean by TTT diagrams. Describe the method of constructing TTT diagrams for an eutectoid steels. Label the various phases in the TTT diagram.