Material Technology - Dec 2012

Mechanical Engineering (Semester 4)

TOTAL MARKS: 80
TOTAL TIME: 3 HOURS (1) Question 1 is compulsory.
(2) Attempt any three from the remaining questions.
(3) Assume data if required.
(4) Figures to the right indicate full marks. 1(a) High speed steels(5 marks) 1(b) Creep resistant materials(5 marks) 1(c) Dislocation jog(5 marks) 1(d) Allotropic forms of iron(5 marks) 2(a) What is recrystalization annealing?Discuss the stages and factor affecting on it?(10 marks) 2(b) Define fracture.Explain brittle,ductile,creep and fatigue fracture.(10 marks) 3(a) Draw Fe-Fe3 C equilibrium diagram showing important transformation Discuss Eutectoid transformation in details.(10 marks) 3(b) Explain griffith theroy pf brittle fracture.What is ductile-brittle transition?(10 marks) 4(a) Explain how to determine from the equilibrium diagram,the composition of two phase that are in equilibrium at any temperature.(10 marks) 4(b) What is peritectic reaction?Explain with example.(10 marks) 5(a) Define a space lattice.What are its important characteristic?(10 marks) 5(b) Define:ferrite,cenentile,austenile,pearlite,martensite and bainite.what are their general characteristic?How they obtained?(10 marks) 6(a) What are the chemical propertise of a materials?How are they measured?(10 marks) 6(b) What is an S-N curve?What useful information is obtained from such curve?(10 marks) 7(a) What are the different methods of diffusion coating?Discuss in the details with its principle & application.(10 marks) 7(b) How would you improve the machinability of a low carbon,medium carbon and high carbon steel by heat treatment?(10 marks)