1.a. Define atomic packing faction. Calculate the coordination No, atomic radius and APF for a HCP crystal structure.

1.b. The surface of 1020 steel with 0.2%C to be carburized at $927^{o}C$. Calculate the time required to increase the carbon content to 0.4% at 1mm below the surface, if the carbon potential at the surface is 1.2% wt . Given D = 1.28 x $10^{-11}C m^{2}C/sec $

z	0.85	0.9	1.0
enf(Z)	0.7707	0.797	0.842

2.a. What is stress relaxation? derive an expression for stress relaxation.

2.b. Define fatigue.Explain different types of stress cycles that cause fatigue failure, with sketches.

3.a what is solid solution? Mention the type of solid solution.Explain the factors given by Hume Rolhery that govern the formation of solid soulution.

3.b Exlain the effect of any 8 alloying elements on the properties of steel.

4.a Draw the Iron Carbon diagram and label all the points and fields in it.Explain the different phases in it.

4.b. Two metals A and B with melting temperatures $850^{o}C$ and $1100^{o}C$ respectively having unlimited liquid solubilities.They form an eutectic solid solution at $600^{o}C$ and a composition of 35% A and 65% B. The maximum solid solubility of A in B is 10% at eutectic temperature and 5% at room temperature.The maximum solubility of B in A is 16% at eutectic temperature and 7% at rom temperature. Assume liquidus, soludus and solvers lines to be straight.

i)Draw the phase diagram and label all the regions.

ii)Determine the NO, relative amount of phases at room temperature for an alloy of 60% A and 40% B.

5.a. Draw a TTT diagram for plain carbon steel and lable the fields.Show the cooling curve which form 100% marten site on it and explain it.

5.b. Give the detailed classification of heat treatment types.Explain Mastempering and Austempering, with sketches.

6.a. What is age hardening? Expalin age hardeninig of at 0.4% Cu alloy showing the micro structure, with sketch.

6.b. Explain the compostiion ,structure and properties of 4types of Cast Iron.

7.a. State and explain the mechanical and electrical properties of ceramic materials.

7.b. How are plastics classified based on sturcture and behaviour? Give the advantages and disadvantages of plastic materials.

8.a. What are smart materials? Write short notes on Piezo electric materials and shape memory alloys.

8.b. What is residual life assessment and its importance? Explain any 3 non destructive testing methods used for assessing residual life.

9.a. Define composite material. Eplain the role of matrix interface and reinforcement in an composite material.

9.b. Explain resin transfer moulding process, with a neat sketch. State it advantages and disadvantages.

10.a. Under Iso-Strain condition derive an expression for Young's modulus of fibre reinforced composites. List the advantages and applications of composite materials.

10.b. With a neat sketch explain injection moulding process and state it's advantages.