Manufacturing Process 3 - Dec 2015

Mechanical Engg. (Semester 5)

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) Define true stress and true strain. Derive expression showing the relationship between true stress and engineering stress as well as true strain and engineering strain.(10 marks) 1 (b) Explain with a neat sketch the hydrostatic pressure in metal working.(5 marks) 1 (c) Write a note on determination of flow stress.(5 marks) 2 (a) Explain the effect of the following on metal working processes (i) temperature, (ii) friction and lubrication.(10 marks) 2 (b) Write a note on: i) deformation zone geometry, (ii) residual stresses in wrought products.(10 marks) 3 (a) With neat sketches, describe various types of forging processes.(6 marks) 3 (b) Explain die design parameters in forging, with a neat figure.(8 marks) 3 (c) Explain ?friction hill concept? and the factors affecting it in forging.(6 marks) 4 (a) Explain with neat sketch of rolling mill (i) four high rolling mill, (ii) tandem rolling mill.(10 marks) 4 (b) Discuss the effect of front tension and back tension on the rolling process, with neat figures.(8 marks) 4 (c) List defects in rolling.(2 marks) 5 (a) Using neat sketches explain Rod drawing and wire drawing.(8 marks) 5 (b) With neat sketch, briefly explain the different features of a drawing die.(4 marks) 5 (c) Explain with neat sketches different method of tube drawing.(8 marks) 6 (a) Give the classification of extrusion processes and explain any two processes with neat sketch.(10 marks) 6 (b) Explain the following:
i) Metal flow and deformation during extrusion
ii) Defects in extrusion.(10 marks) 7 (a) With neat sketches, explain combination die and progressive die. List the type of components produced in sheet metal work.(10 marks) 7 (b) Write a note on forming limit criteria (Keeler-Goodwin diagram).(5 marks) 7 (c) It is required to punch a hole of 10 mm dia in a mild steel plate of 10 mm thickness. Determine whether it is feasible or not, taking shear strength of the plate as 600 N/mm² and compressive strength of the punch as 2000 N/mm². If it is not possible, what could be done to produce this hole?(5 marks) 8 (a) What is HERE? Explain explosive forming, with a neat figure.(8 marks) 8 (b) With a flow chart, explain in detail the powder metallurgy process.(8 marks) 8 (c) Explain any two methods of production of metal powder with sketches.(4 marks)