JNTU Exam Papers-B-Tech-Metallurgy And Material Science-November 2008

JNTU II B.Tech I Semester Regular Examinations, November 2008

METALLURGY AND MATERIAL SCIENCE

( Common to Mechanical Engineering, Mechatronics, Production

Engineering and Automobile Engineering)

SET-4

 

 1. Write a short note on

(a) Nucleation and growth

(b) Micro segregation and macro segregation

(c) Homogeneous and Heterogeneous nucleation

(d) Directional solidification.

 

2. (a) Why is an octahedral void called Octahedral?

(b) Draw a unit cell of FCC and also show atleast one octahedral void in it. How many such voids are present in it?

(c) Draw a unit cell of BCC and show atleast one octahedral void in it. How many such voids are present in it?

(d) Draw a unit cell of HCP. Show one of the octahedral holes in it. How many octahedral holes are present in it?

 

3. Duralumin alloy rivets used in aircraft construction are kept at -400C after solution

treatment. Whenever required they are taken out and riveted on the spot. Explain

the reason for keeping them at -400C and also explain how rivets operation at room

temperature strengthen the rivets?

 

4. (a) Give the classification of stainless steels?

(b) Explain each type of steel with chemical composition, microstructure, properties and applications?

 

5. (a) What is Martensite? Distinguish between Lath Martensite and Accicular martensite.

(b) Discuss briefly Nitriding of steels.

 

6. Discuss the following alloys:

(a) Cupronickels

(b) Beryllium Bronzes.

 

7. (a) Compare the properties of crystalline ceramics and glass ceramics.

(b) Why annealing and tempering operations are performed on glass? Describe.

 

8. (a) What is the role of matrix in a composite material? Discuss various types matrix materials.

(b) Indicate any one important metal matrix composite and mention its characteristics, properties and applications.

 

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