JNTU PAPERS,B-Tech,I- Semester,Physical Metallurgy, November 2008

JNTU PAPERS

JNTU,B.Tech,I- Semester, Physical Metallurgy, November 2008

 (Metallurgy & Material Technology)

SET-4

1. Give an account on the following:

(a) Condenser system

(b) Light filters

(c) Objective lens

2. With a neat sketch of BCC structure, find effective number of atoms, packing factor

and coordination number.

 

3. (a) What are the possible alloy structures. Explain briefly the different alloy structures with suitable examples.

(b) Explain why if one element is highly electronegative and the other highly electropositive the intimate mixture of them is not an alloy.

 

4. (a) What are the important characteristics of grain boundaries? Discuss the role

of grain boundaries for low temperature and high temperature applications.

(b) Differentiate between a crystal, a dendrite, a grain and a grain boundary.

 

5. (a) What is allotropy? Discuss various allotropic forms of iron and their properties.

(b) Explain why increase of pressure may give allotropic transformation to close

packed structures.

 

6. (a) Explain the phase changes that take place when an eutectoid steel is cooled

from 9000 C to RT.

(b) Distinguish between steels and cast irons and highlight the importance of each

of them as engineering materials.

 

7. Write short notes on the following:

(a) Effect of coarse and fine pearlite on mechanical properties or steels.

(b) Upper bainite and lower bainite

(c) Lath martensite & plate martensite

(d) A thermal martensite & isothermal martensite.

 

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.

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