Material Science & Metallurgy - Jun 2013
Mechanical Engineering (Semester 4)
TOTAL MARKS: 100
TOTAL TIME: 3 HOURS (1) Question 1 is compulsory.
(2) Attempt any four from the remaining questions.
(3) Assume data wherever required.
(4) Figures to the right indicate full marks. 1 (a) With neat sketch,explain body centred cubic face centred and closed packed hexagonal structures with example.(9 marks) 1 (b) Derive expression for atomic packing factor of BCC,FCC and HCP structure(7 marks) 1 (c) Briefly explain the different types of point defects (4 marks) 2 (a) With the help of stress -strain digram. Explain the behaviour of ductile and brittle materials (8 marks) 2 (b) The following data have been obtained in hardness test of specimens. Calculate the hardness number. Assume dia of ball indenter =10mm.
(6 marks) 2 (c) Define the following terms Toughness, Resilience, Proof stress and ductility.(6 marks) 3 (a) With neat digram , explain the feature in the following:
Fatigue(12 marks) 3 (b) Explain the three stages of creep with a neat sketch and its characteristic (8 marks) 4 (a) With net diagram ,explain the process of nucleation (4 marks) 4 (b) Write a note on Gibbs phase rule with an example (4 marks) 4 (c) With the help of cooling curve,explain how solidification process begins in pure metals (6 marks) 4 (d) Briefly explain the rules behind the solid solubility(5 marks) 5 (a) Construct the Ag-Cu phase diagram using following data;
Melting point of Ag=960.5°c
Melting point of Cu=1085°C
Eutectic composition =28.1%Cu
Maximum solubility of Ag in Cu and Cu in Ag is 8%
maximum solubility of Cu in Ag in Cu is 2%.Assume the liquids ,solidus and solves lines are straight .calculate:
Amount of eutectic in 20% Cu,80%Ag alloy at 700°c and
Percentage and composition of solid phase in 60%Cu and 40% Ag alloy 400°C.(10 marks) 5 (b) What is level rule? Explain how it is useful.(5 marks) 5 (c) What is phase diagrams?how are they classified?(5 marks) 6 (a) Draw Iron-carbon equilibrium diagram and explain primary crystallization of steel hypoeutectic cast iron hypereutectic cast iron(10 marks) 6 (b) Define the following annealing ,normalization, tempering , carburizing and nitriding(10 marks) 7 (a) How cast iron classified ?What are the properties of cast iron?(8 marks) 7 (b) How generally steels are classified ?consider at least two composition mixture .mention its application and advantages(6 marks) 7 (c) Explain the composition ,properties and used of at least two copper based alloys(6 marks) 8 (a) Derive an expression for load distribution in a composite for longitudinal loading of fibre reinforced composite(10 marks) 8 (b) With a neat diagram ,explain the hand laminating process(10 marks)