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-2

1. (a) Name various methods of illumination in metallurgical microscope and briefly

explain each one of them.

(b) What is conical stop illumination? Discuss its features.

2. (a) Indicate the crystal structures for copper, aluminium, magnesium, alpha iron,

gold, silver, titanium and zinc.

(b) Discuss stacking fault with reference to FCC metals.

(c) With a neat sketch, explain metallic bond.

 

3. (a) What are the different types of solid solutions. Explain interstitial solid solution with suitable examples.

(b) Discuss in detail the necessity of alloying and explain the same with four

specific examples.

 

4. (a) Describe how the liquidus and solidus of a binary isomorpous phase diagram

can be determined Experimentally.

(b) Write the Equation of Gibb’s phase rule. Define and Explain each of the terms

in the equation.

 

5. (a) What is allotrophy? What is allotrophic transformation? Give any three

examples which show allotrophic transformation and explain them.

(b) Explain the allotropic transformation of Iron.

 

6. (a) Compute the mass fraction of ferrite and cementitie in pearlite.

(b) Explain the differences between hypo eutectoid and hypereutectoid steels.

(c) In a hypo eutectoid steel both eutectoid and proeutectoid ferrite exist. Explain

the differences between them.

 

7. (a) How are the critical temperatures of steel on heating and cooling designated.

(b) If a steel is heated to temperature just above its MS temperature, and then

quenched, Martensite does not form. Explain why?

(c) ‘When martensite form, expansion occurs’. Explain why?

(d) Explain why martensite is not always hard and brittle.

8. (a) What is S curve? How do you draw it? Classify the types of ‘S’ curves. Give

at least three heat treatment cycles in which ‘S’ curves find direct applications.

(b) Discuss the factors affecting the ‘S? curves.

 

 

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