Material Science and Engineering Question (Winter 2010)

group A

1
a) What are Bravais lattices? Explain in brief the differences in stacking
sequence of FCC and HCP crystal structure.
b) Caculate the atomic packing factor (APF) for the FCC crystal structure.
c) What are point defects and how are they created? Discuss different types
point defects in brief .
d) Discuss major differences between edge and srew dislocation.
2
a) What is Gibbs phase rule ?Explain its application with reference to
binary phase digram s.
b) Write the eutectoid reaction in Fe-Fe3C system and find thr amount of different phases at the eutectoid point .
c) What is true stress ? Deduce the relationship between engineering and true stress ?
d) What is meant by the toughness of material ?How is it measured and assessed?

3 a) Differentiate between ductile fracture and brittle fracture ?
b) Explain the S-N curve with respect to ferrous and non ferrous material?
c) Explain how deformation takes place by twinning .
d) Differentiate between cold working and hot working.
4 Write notes on any four of the following:
a) Fick’s law of diffusion
b) Creep behaviour in metals
c) Hume Rothery’s rules
d) Deformation in polycrystalline materials
e) Solid solution strengthening
f) Recovery ,recrystallization and grain growth.
GROUP-B
5 a) Draw the iron-iron carbide phase diagram. Clearly indicating the phase present at different temperatures and carbon content.
b) Explain in brief the time-temperature-transformation(T-T-T) diagrams.

6 a) Distinguish between thermal heat capacity and thermal heat content .
b) Explain the types of magnetism in brief .
c) Differentiate between the instrinsic and extrinsic type semiconductor.
d) Discuss the mechanism of sintering of ceramic materials .
7 a) Discuss different mechanism of polymerization .
b) What are the factors affecting mechanical properties of polymers ?
Discuss
c) What are composite materials ? Briefly classify the composite materials.
8 A)Write short notes on any four of the following
a) Annealing and normalising
b) Thermoplastic and thermosets
c) Surface hardening
d) Basic refractories
e) Continuous cooling transformation(CCT)digrams
f) Zone theory of solids
GROUP-C
9 Give brief and precise answer to the following
i) Define hardenibility
ii) What is isomorphous system ?
iii) State the Hall-Petch equation ,explaining the meaning of each symbol.
iv) What is pertectic reaction?
v) What is Bauschinger effect ?
vi) What is critical cooling rate ?
vii) What are the main material for cryogenic application ?
viii) What is glass transition temperature(Tg)?
ix) Define fracture toughness of a material .
x) What is superconductivity?