II B.Tech I Semester Supplimentary Examinations, February 2008
(Metallurgy & Material Technology)
1. Name various microscopy methods for enhancing contrast and briefly explain any three of them.
2. (a) Discuss polymorphism and allotropy with suitable examples.
(b) Explain stepwise determination of Miller indices of a plane with an example.
(c) Explain why gold, copper and aluminium exhibit good ductility.
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) Show that the homogenous nucleation barrier G = 163 3(G)2 neglecting strain energy effects.
(b) Write a short notes on super cooling.
5. What are the several equilibrium changes and reactions that take place in the solid state? Explain them fully with suitable examples.
6. (a) Discuss briefly all the possible Alloy phases in binary alloy.
(b) Discuss the properties & Applications of copper and its Alloys.
7. (a) What is subzero treatment? Under what conditions this treatment is given to hardened components? Explain.
(b) Discuss the effect of time and temperature on transformation of austenite to pearlite or pearlite to austenit.
8. (a) Discuss the effect of various alloying elements on the shape, size and poison of TTT diagrams.
(b) Define and explain ‘critical cooling rate’. Show the same on a TTT diagram.
(c) What factors influence critical cooling rate? Explain.