JNTU Physical Metallurgy Exam Paper Nov 2008

JNTU Physical Metallurgy Exam Paper Nov 2008

(Metallurgy & Material Technology)

SET-2

1. Give an account on the following:

(a) Condenser system

(b) Light filters

(c) Objective lens [6+5+5]

2. (a) The atomic radius of Iron is 1.24 A0. Calculate the lattice parameter of BCC and FCC iron.

(b) Determine the number of lattice points per unit cell in the simple cubic, face centered cubic and body centered cubic crystal systems. [7+9]

3. (a) Give an account on Miller indices of planes with examples.

(b) Explain Miller indices of direction with examples. [8+8]

 

4. (a) What are the different types of solid solutions. Explain interstitial solid solu-

tion with suitable examples.

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

specific examples. [8+8]

 

5. (a) Describe and illustrate the solidification process of a pure metal in terms of

the nucleation and growth of crystals.

(b) During the solidification of a metal explain the major differences between an

Embryo and a nucleus? Also explain what is the critical radius of a solidifying

particle. [8+8]

 

6. Neatly sketch to scale the pb-Sn Equillibrum diagram from the following data.

Melting point of Pb = 3270C

Melting point of Sn = 2320C.

Eutectic temperature = 1830C.

EUTECTIC composition = 61.9% Sn.

Maximum solubility of Pb in Sn at 1830C = 2.6%

Room temperature solubilities are negligible. From the above diagram determine

the following for an alloy containing 25% Sn.

(a) The freezing Range

(b) The relative proportions of phases at 1920C.

(c) The compositions of the phases at 1920 C. [16]

 

7. (a) Classify copper alloys. Discuss the mechanism of increasing strength of copper

alloys.

(b) Calculate the relative amounts of various phases that are present in 0.5% C

steel, just above & just below the peritectic temperature. [8+8]

 

8. (a) Differentiate between CCC & TTT diagrams.

(b) Explain about the bainitic transformation.

 

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