Material Science & Metallurgy - Jun 2015

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) What do you mean by co-ordination number? With a neat figure, write co-ordinations number for HCP structures.(4 marks) 1 (b) What is Crystal Imperfections? With a neat sketches, explain line defects and surface defects.(12 marks) 1 (c) Explain briefly, Factors affecting diffusion.(4 marks) 2 (a) Differentiate between: i) Engineering Stress of True stress ii) Engineering Strain and True strain. Derive the relation between Engineering Strain and True Strain.(8 marks) 2 (b) Explain with neat sketches, plastic deformation by
i) Slip ii) Twinning.(8 marks) 2 (c) Draw the stress-strain curve for a ductile material and explain the important points on the curve.(4 marks) 3 (a) What do you mean by Type-I, Type-II and Type-III fractures? Explain with neat sketches.(6 marks) 3 (b) What is Creep? Explain creep curve, with neat sketch.(8 marks) 3 (c) Explain with neat sketches. Typical fatigue stress cycles (Fatigue Loading).(6 marks) 4 (a) Explain with neat sketch, the mechanism of solidification.(5 marks) 4 (b) What is Homogeneous Nucleation? With a neat sketch, derive the relation for free energy charge, δfe.(10 marks) 4 (c) Explain Hume-Rothary Rules for formation of solid solutions.(5 marks) 5 (a) Explain briefly the construction of phase diagram using cooling curve, with a neat sketch.(5 marks) 5 (b) Name the different types of phase diagrams. Explain with a neat sketch solid solution phase diagram (Complete solubility).(10 marks) 5 (c) Draw the Iron-Carbon Equilibrium diagram and label all the phases.(5 marks) 6 (a) What do you mean by T-T-T curves? Explain with neat sketches, the construction of TTT curves for plain carbon steel.(10 marks) 6 (b) Explain with neat sketch, Pack carburizing.(5 marks) 6 (c) Explain with neat sketch, Flame Hardening.(5 marks) 7 (a) Explain the Composition, Properties and Applications of
i) Gray cast iron ii) Malleable cast iron.(10 marks) 7 (b) Explain the Composition, Properties And Applications of
i) Aluminium-Copper Alloys
ii) Aluminium-Zinc Alloys.(10 marks) 8 (a) Define the Composite material. Explain the different types of Matrix Materials and Types of Reinforcements.(10 marks) 8 (b) Explain with a neat sketch, the 'Pultrusion' process for producing FRP's.(6 marks) 8 (c) Give the Advantages and Applications of composites.(4 marks)