Manufacturing Process 2 - Jun 2014

Mechanical Engg. (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 suitable sketches, explain different types of chips produced during machining.(7 marks) 1 (b) Discuss the causes for tool failure.(7 marks) 1 (c) In an orthogonal cutting the following observation were made: Feed=0.25mm/rev Chip thickness=0.8mm
Depth of cut=2mm Length of chip -tool contact=0.5mm
Working rake angle=0° cutting force=F=1800N
Axial trust=900N
Determine:
i) The mean angle of friction of tool face .
ii) The mean shear strenghth of the work material.
iii) The maximum frictional stress on tool face.(6 marks) 2 (a) Draw the sketches showing sources of heat and heat distribution to various elements during metal cutting.(10 marks) 2 (b) Discuss the effect of temperature an hardness for different cutting tool material.(6 marks) 2 (c) List and explain the characteristics features of good cutting tool material.(4 marks) 3 (a) What are the difference between a capstan lathe and a turret lathe?(6 marks) 3 (b) Find the time required for taking a complete cut on a plate 6000mm length × 300mm width if the cutting speed is 9 m/min. The return time to cutting ratio is 1:4 and the feed is 3mm. The clearance at each and is 75mm.(6 marks) 3 (c) List out the differences between shaper and planer.(8 marks) 4 (a) With suitable sketches, explain the following operation using drilling machine:
i) Trepanning
ii)Tapping
iii) Boring
iv) Reaming(12 marks) 4 (b) Define x,y and z axes on a NC drill machine.(4 marks) 4 (c) Explain point-to-point positioning control system of tool in NC system.(4 marks) 5 (a) With suitable sketches explain the following milling machine operation:
i) Form milling
ii)Gang milling(8 marks) 5 (b) Draw the neat sketches showing all the elements of plain milling cutter and label all parts.(6 marks) 5 (c) Name various work holding devices used in milling machine and indicate their uses.(6 marks) 6 (a) What are the difference of grinding machine over shaping machine?(5 marks) 6 (b) List and explain different abrasive materials used in grinding wheel.(5 marks) 6 (c) How a grinding wheel is marked? Describe Indian standard marking system.(5 marks) 6 (d) Briefly explain the constructional features of grinding machine.(5 marks) 7 (a) What is broach? How broaches are classified?(5 marks) 7 (b) What are the limitations of broaching process?(5 marks) 7 (c) Briefly explain the following surface finishing operations:
i) Buffing
ii)Polishing.(10 marks) 8 (a) With suitable sketches, explain Abrasive jet machining.(5 marks) 8 (b) Discuss the effect of cutting parameters in USM(5 marks) 8 (c) What are the advantages and disadvantages of ECM?(5 marks) 8 (d) List the essential requirements of dielectric fluid used in EDM.(5 marks)