JNTU II B.Tech I Semester Regular Examinations, November 2008
METALLURGY AND MATERIAL SCIENCE
( Common to Mechanical Engineering, Mechatronics, Production
Engineering and Automobile Engineering)
1. (a) Define crystallization of metal? How is that commercial alloy invariably solidify with heterogeneous nucleation?
(b) What factor favours the formation of fine grained material? How is a large
single crystal being produced?
2. (a) Discuss in detail the necessity of alloying with few examples.
(b) Explain how are alloys actually made in industry?
3. (a) Define cast irons ? Explain the cooling history of 4.3% C in Fe-Fe3C system by drawing cooling curve?
(b) Calculate proportionate of different phases for 2.8%C in Fe-Fe3C diagram at
12000C, 11730C, and 6000C. Also draw the microstructures at room temperature?
4. (a) Why stainless steels are stainless?
(b) Is it possible to harden 18%Cr-8%Ni steels by heat treatment?
(c) Why Austenitic stainless steels prone to welddecay? How can you avoid weld decay?
5. (a) Distinguish between hardness and hardenability.
(b) Critically discuss Pack carburizing of steels.
6. (a) What are light metals? Explain the important characteristics of aluminium and its alloys.
(b) Describe alloy and temper designation of Al and its alloys.
7. (a) Calculate the density of FeO which has an NaCl-type structure. (assume stoichiometry). Radius of Iron is 0.74A0 & oxygen is 1.40 A0.
(b) Discuss briefly the structure, properties and uses of Al2O3.
8. (a) Explain how to improve damping ability of a composite.
(b) Compare and contrast whisker and particulate reinforced composites.