Manufacturing Process 1 - May 2014

Mechanical Engg (Semester 3)

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.

Answer any one question from Q1 and Q2

1 (a) Explain the following defects in casting components with their causes and remedies. (i) Mismatch (ii) Blow holes(6 marks) 1 (b) A 200 mm long down sprue has an area of cross section of 650 mm² where the pouring basin meets the down sprue. A constant head of molten metal is maintained by the pouring basin. The molten head flow rate is 6.5×10⁵ mm³/s. Considering the end of the down sprue to be open to atmosphere and acceleration due to gravity as 10⁴ mm/s² at it ends , find the area of the sprue at the end.(6 marks) 2 (a) Mention the ingredients present in the moulding sand and its effect on the properties of moulding sand.(6 marks) 2 (b) Explain in detail Lost-Wax casting process in details.(6 marks)

Answer any one question from Q3 and Q4

3 (a) A solid material mode of stainless steel is 50 mm in diameter and 76mm in height, It is reduced in height by 50% with the help of open-die forging. The work material has a flow curve defined by K=350 Mpa and n=0.17. If coefficient of friction is 0.1, calculate the forging force at the end of stroke.(6 marks) 3 (b) Explain (i) Wire Drawing (ii) Shot Peening.(6 marks) 4 (a) Explain working principles of forward and backward extrusion process.(4 marks) 4 (b) Write down difference between Hot working and cold working.(5 marks) 4 (c) Briefly explain the Rotary swagging.(3 marks)

Answer any one question from Q5 and Q6

5 (a) With the aid of sketches, compare the principles of compression moulding, injection moulding and extrusion moulding. Describe where each would be used in terms of material and components.(7 marks) 5 (b) Explain in detail vacuum process.(6 marks) 6 (a) Explain in detail Gas Tungsten Arc Welding.(6 marks) 6 (b) Compare with neat sketches leftward and rightward welding techniques. Specify the merits and limitations of both the techniques.(7 marks)

Answer any one question from Q7 and Q8

7 (a) A hole 100mm diameter is to be punched in a steel plate of 6 mm thick. The material is cold rolled C30 steel for which the maximum shear strength can be taken as 370 N/mm² with normal clearance on the tools, cutting is completed at 40% penetration of the punch. Giving suitable diameter for the punch and die, and shear angle on the punch in order bring the work within the capacity of a 200KN press available in the shop.(7 marks) 7 (b) Describe the following terms:
i) Sheet utilization ratio.
ii)Centre of pressure
iii)Shear or punch and die.(6 marks) 8 (a) Explain taper turning attachment with a neat diagram. Give its merits and demerits.(7 marks) 8 (b) A part of 25 cm in diameter and 50 cm length is to be turned down to 23.5 for the entire length . Assume feed as 1 mm/ rev . and cutting speed as 135 mpm . The maximum allowable depth of cut is 5 mm. what are the feed speed, spindle r.p.m and cutting time. Take over travel as 12.5 mm.(6 marks)