Assigment Manufacturing Process

FACULTI OF MECHANICAL ENGINEERING UNIVERSITI MALAYSIA PAHANG BMM3643 (Sem II 2012/13) Assignment 4 1. a) What distinguishes machining from another(prenominal) manufacturing processes? b) What is a machining center? c) How burning(prenominal) is the control of cutting-fluid temperature in operations performed in machining centers? excuse. (8 marks) 2. a) What are the primary considerations in tool selection? b) What is the advantage of a helical-tooth cutter over a straighttooth cutter for slab milling? c) What are the consequences if a cutting tool chips? (8 marks) 3. ) why might it be desirable to consumption a heavy depth of cut and a light viands at a given speed in turning? b) Explain the reasoning behind the various design guidelines for turning. c) In drilling, the deeper the hole, the greater the torque. Why? (8 marks) 4. a) For producing flat jumps in mass production machining,how does face milling protest basically from peripheral milling? b) Why is end milling such a n important versatile process? c) Why is grain spacing important in craunch wheels? Explain the relationship between grit size of it and surface finish. (8 marks) 5. ) Why has the wire-EDM process become so widely utilise in industry, especially in tool and die manufacturing? Explain. e) What is meant by the confines overcut in electric realise machining? f) What is the nature of the surface obtained by electro discharge machining? (8 marks) 6. g) Estimate the time required for face milling an 20. 32 cm-long, 7. 62 cm-wide hardiness block using a 2032 cm-diameter cutter with 12 HSS teeth. (Given employ the high-speed-steel tool, lets take a recommended cutting speed for brass (a copper alloy) at 90 m/min = 1. 5 m/sand the maximum feed per tooth as 0. mm) h) In a surface grinding operation performed on hardened plain carbon steel, the grinding wheel has a diameter = 200 mm and width = 25 mm. The wheel rotates at 2400 rev/min, with a depth of cut (infeed) = 0. 05 mm/pass and a crossfeed = 3. 50 mm. The reciprocating speed of the work is 6 m/min, and the operation is performed dry. Determine i) the length of contact between the wheel and the work, ii) the ledger rate of metal removed. iii) If there are 64 active hominy grits/cm2 of wheel surface, estimate the number of chips formed per unit time. (10 marks)