Code No: RR211801 Set No.

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II B.Tech I Semester Supplimentary Examinations, November 2007
PHYSICAL METALLURGY
(Metallurgy & Material Technology)
Time: 3 hours Max Marks: 80
Answer any FIVE Questions
All Questions carry equal marks
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1. (a) What are lenses? Name different types of lenses and briefly explain each one
of them.
(b) Name the factors by which optical characteristics of lenses are determined and
briefly discuss. [8+8]

2. (a) Give an account on Hume-Rothery classification of metals.

(b) With a neat sketch, discuss metallic bond and characteristics associated with
it. [8+8]

3. (a) Discuss procedure for finding the Miller indices for directions with suitable
examples.
(b) Why titanium and magnesium exhibit poor ductility? [8+8]

4. (a) Find out electron-to-atom ratio for the following compositions.

Ag3 Al, Cu5 Zn8 , Cu9 Al4 , CuZn3 and Cu3 Sn
(b) Discuss various types of solid solutions. [8+8]

5. (a) Suppose that the solid nickel was able to nucleate homogeneously with an
under cooling of only 220 C. How many atoms would have the group together
spontaneously for this to occur.
Assume that the lattice parameter of the solid FCC nickel is 0.356 nm.
Data
Nickel freezing temperature : 14530 C
Surface energy : 255 × 10−3 J/m2
Latent heat of fusion : 2756 × 106 J/m2
(b) Explain the difference between planar growth and dendritic growth. [8+8]

6. (a) What is Gibb’s phase rule? Explain it’s importance.

(b) Explain the method of plotting an equilibrium diagram for a binary alloy by
the use of cooling curves. [4+12]

7. Explain the following

(a) Eutectiod & peritectiod reactions in Fe-Fe3 C diagram.

(b) Effect of Alloying elements on steel. [8+8]

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

(b) Explain about the bainitic transformation. [10+6]

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Code No: RR211801 Set No. 1
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Code No: RR211801 Set No. 2
II B.Tech I Semester Supplimentary Examinations, November 2007
PHYSICAL METALLURGY
(Metallurgy & Material Technology)
Time: 3 hours Max Marks: 80
Answer any FIVE Questions
All Questions carry equal marks
⋆⋆⋆⋆⋆

1. Name various microscopy methods for enhancing contrast and briefly explain any
three of them. [16]
2. (a) With a neat sketch, show the octahedral positions in FCC structure. Also
calculate the radius of the octahedral void in the FCC structure relative to
the radius of the atom.
(b) What is stacking sequence? Write the stacking sequence for FCC and HCP
metals. [10+6]
3. Write short notes on the following:
(a) Transformation of indices
(b) Miller indices of a plane and direction. [8+8]
4. (a) What is a solid solution? Give the classification and explain the rules for the
formation of solid solutions.
(b) Explain why atomic size difference is only 4.2% still Zn can dissolve up to
38.4% in Cu? [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. (a) Draw a typical equilibrium diagram of a binary system in which each metal
lowers the melting point of the other and both are mutually soluble to a limited
extent in the solid state. Label the phases.
(b) What factors favour a binary system to follow isomorphous alloy? Explain.
[8+8]
7. (a) Explain with neat diagrams how the micro-structure of a pure metal may
change with additions of alloying elements.
(b) What is allotropy & Discuss various allotropic forms of Iron & their properties.
[8+8]
8. (a) Draw the T-T-T diagram for a eutectoid steel label the various regions &
lines. Explain the effect of various elements on the position and shape of
T-T-T diagram..

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Code No: RR211801 Set No. 2
(b) Explain the Pearlitic & Martensitic transformation. [8+8]

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Code No: RR211801 Set No. 3
II B.Tech I Semester Supplimentary Examinations, November 2007
PHYSICAL METALLURGY
(Metallurgy & Material Technology)
Time: 3 hours Max Marks: 80
Answer any FIVE Questions
All Questions carry equal marks
⋆⋆⋆⋆⋆

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. [8+8]

2. (a) Give an account on Hume-Rothery classification of metals.

(b) With a neat sketch, discuss metallic bond and characteristics associated with
it. [8+8]

3. Write short notes on the following:

(a) Transformation of indices

(b) Miller indices of a plane and direction. [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) Suppose that the solid nickel was able to nucleate homogeneously with an
under cooling of only 220 C. How many atoms would have the group together
spontaneously for this to occur.
Assume that the lattice parameter of the solid FCC nickel is 0.356 nm.
Data
Nickel freezing temperature : 14530 C
Surface energy : 255 × 10−3 J/m2
Latent heat of fusion : 2756 × 106 J/m2
(b) Explain the difference between planar growth and dendritic growth. [8+8]

6. (a) What information may be obtained from an equilibrium diagram?

(b) Discuss the importance of equilibrium diagrams in the development of new
alloys.
(c) The departure from equilibrium in natural freezing of protective alloys is usu-
ally very large. Why?
(d) Draw and explain the cooling curve for a solid solution. [4+4+4+4]

7. (a) Explain with neat diagrams how the micro-structure of a pure metal may
change with additions of alloying elements.

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Code No: RR211801 Set No. 3
(b) What is allotropy & Discuss various allotropic forms of Iron & their properties.
[8+8]

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

(b) Explain about the bainitic transformation. [10+6]

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Code No: RR211801 Set No. 4
II B.Tech I Semester Supplimentary Examinations, November 2007
PHYSICAL METALLURGY
(Metallurgy & Material Technology)
Time: 3 hours Max Marks: 80
Answer any FIVE Questions
All Questions carry equal marks
⋆⋆⋆⋆⋆

1. (a) What are the common defects of lenses? Briefly explain each one of them.
(b) What are the various types of objective lenses? Briefly discuss each one of
them. [8+8]
2. (a) Define octahedral and tetrahedral sites and discuss with reference to BCC and
FCC structures.
(b) Give an account on bonding and material property. [8+8]
3. Write short notes on the following:
(a) Transformation of indices
(b) Miller indices of a plane and direction. [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) Explain the differences between
i. Coherent
ii. Partially coherent
iii. Incoherent interfaces.
(b) Explain how does the interfacial energy vary with coherency. [9+7]
6. What is meant by a ‘peritectic’ reaction? Sketch an Equilibrium diagram of a
system containing such a reaction and describe the Equilibrium cooling of two
typical alloys, at least one of which undergoes a peritectic reaction. What is the
effect of faster cooling on the reaction. [16]
7. Distinguish between peritectoid & Eutectoid reaction. What is the practical im-
portance of the alloys undergoing these transformations [with examples] [16]
8. (a) Draw the T-T-T diagram for a eutectoid steel label the various regions &
lines. Explain the effect of various elements on the position and shape of
T-T-T diagram..
(b) Explain the Pearlitic & Martensitic transformation. [8+8]

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