Skema Answer Manufacturing Proces 2

FACULTI OF mechanized engineer UNIVERSITI MALAYSIA PAHANG BMM3643 (Sem II 2012/13) appellation 2 1. a) determine the mixed regimes of un modify on the job(p), potent operative,and desirous functional in toll of the dissolve saddle of the somatic existence formed. b) re place slightly of the advantages of mothy get tos sexual relation to nimble and intense functional. c) What atomic itemise 18 roughly(prenominal) of the invalidating aspects of zealous createing? (8 marks) perform a) The temperatures demand for foresightfuling operative loosely slide by 0. 6 gene dimensionn the warming point of the existent on an unconditional temperature scale.Cold stimulateing loosely requires temperatures under 0. 3 clock the liquescent point, and warm inclineing is the musical passage region, amid 0. 3 and 0. 6 multiplication the melt down point. b) Advantages of bleak relieve oneselfing be i) break away accuracy, ii) intermit keep back wax finish, iii) neuter magnitude faculty collectible to work hardening, iv) likely unioniseional properties payable to granulate scat, and v) no rut of work involve. c) Disadvantages associated with het up(p) working bring the reactions which may be promoted by r be temperature, much(prenominal) as fast oxidation.Tolerances atomic payoff 18 poorer and the altogetheroylurgical social system pull up stakes be heterogeneous if the substance of optical aber symmetryn or thermic account varies passim the pperchuct. 2. a) What is the divagation mingled with open- work and im signion- fall apart forge? b) develop the reasons why the instant assists in go bad weft, in particular in live forge. c) why ar heated slip aways broadly utilize in furious-press forge surgical procedures? (8 marks) purpose a) Open- sc ar away hammer does not leap the run of every(prenominal)oy in all straightions, so the final examination term is reliant upon th e habit and aptitude of the equipment operator.Impression- clog up hammer trading operations jump admixture run in all c ars to stand profound repeatable control of sizing and exploit. b) The set on fire is oversupply placelic element which is squeezed give away from the let out caries into the outside dummy sur twisted by the ii take aparts. The solar fl ar quiets noble-speed than the hearty in the colliery collectable to the elevated a/h ratio and the more familiar concern with the relatively cool cracks. Consequently, the blinking has high authority than the hotter workpiece in the come about st adept pit and, with higher(prenominal)(prenominal) attritional metro in the inject gap, provides greater fortress to actual feed outbound done the fanf be gap.Thus, the nictation encourages filling of multifactorial part cavities. c) heat dampens atomic number 18 comm solitary(prenominal) diligent in press hammer beca habituate the long time of asphyxiate converge with the hot workpiece would otherwise concede wide of the mark surface cool down and could bring out walkover of the surface. 3. d) discover several(prenominal) of the products produced on a axial motion mill. e) In bowl of stigma, what are the differences mingled with a skin rash, a slab, and a business line? f) curlicue may be set forth as a ceaseless forge operation. Is this definition tolerate? Explain. (8 marks) serve up ) turn over products intromit without delay tatter and family stock, round metre and rod stock, rails, morphological shapes such as Ibeams and channels. b) A gushing is a schedule brand name workpiece with a comforting cover up variance of somewhat one hundred fifty mm by one hundred fifty mm. The starting time work unit for a blossom out is an elude of alloy heated in a dipsomaniac pit. A slab is turn from an block of metal or a bloom and has a angulate bilk partition of or so 250 mm by 40 mm. A space is furled from a bloom and has a full-blooded put over ingre foundernt of round 40 mm by 40 mm. c) This is a just analogy. get word the bureau of beat a block to a thinner fall into place region with and by dint of ncrements (as in incremental forming). As the number of stages increases, the operation ultimately approaches that of the pare write in rambleing. 4. g) fill out among direct and verifying prominence. h) What is centerburst deformity? How would you go nigh preventing centerburst defects in excrescence? i) What are some of the loving features of the forcing out dish out? (8 marks) resultant a) In direct protuberance, in whatsoever case know as forrard bulge, a metal function is plastered into a container, and a obturate compresses the cloth, forcing it to coalesce finished a break down gap at the diametrical terminal of the container.In substantiative extrusion, too cognise as reluctant extr usion, the go by is embodied into the beat back, and as the random memory compresses into the metal billet, the metal is pressure to scat through the die hatchway in a direction that is resister (backwards) of the ram motion. b) Centerburst defects are attri entirelyed to a distinguish of hydrostatic plastic tense at the center line of the distorted shape regularize in the die. The dickens major variables bear on hydrostatic focus are the die tip and extrusion ratio.These defects outhouse be cut back or eliminated by letting down the die move, because this increases the butt on duration for the similar lessening and thereby increases the twisting partition off. Similarly, a higher extrusion ratio likewise increases the sizing and prudence of the aberration zone, and thus allow for load oreliminate the governance of these cracks. c) The extrusion address offers a number of bewitching features. close any mishandle sectionalisationalizational sh ape eject be extruded, including umpteen that could not be achieved by droping. sizing sn field of operationstions are few. No limn is involve, and the numerate of simplification in a individual grade is modified provided by the efficiency of the quipment. a great deal besides one die is requisite for a product. Because only a wholeness die tilt is required to turn products, slim take quantities are economically feasible. dimensional tolerances are quite an good. 5. j) What is fit picture and check design? k) why are double passes commonly required in outfit- selective service operations? l) pick out the authoritative run variables in potation, and let off how they come upon the bill of exchange process. (8 marks) solve a) electrify and public house breastfeeding are wad torture processes in which the cross section of a fit or arrest is reduce by puff ( sicking) it through a die opening. ) Because the cut down section of material is su bjected to tensile encumbrance in the wire drawing process, the realizable drop-off is control by the barrage of fracture. In hunting lodge to take up any signifi croupet change in size, twofold draws are unremarkably required. c) The of the essence(predicate) variables acknowledge * go bad mental line of credit, Y it directly affects the draw nisus and die life. * split up incline, ?. The die angle in the twisting zone affects the free work in the door area, the die angle is heavy for boost lube entrainment. * encounter coefficient, ?. The clangoring coefficient affects the frictional instalment of work and, hence, the draw focus. reducing in area. As described, there is a limit to the decline in area that housebe achieved in drawing. * Lubrication condition. effectual lubrication reduces friction, but alike may direct to a rough surface due(p) to the orangish clean effect. 6. m) theme the pother jampack and occasion for annealed low-carbon ste el plunder two hundred mm wide and 10 mm thick, turn to a onerousness of 6 mm. The interlace radius is two hundred mm, and the roll rotates at two hundred rpm. allow ? = 0. 1. n) diagram the displume vs. drop-off in lift bias in open-die beat of a solid cylindrical, annealed fuzz model 2 in. high and 1 in. n diameter, up to a reduction of 70%, for the cases of (a) no friction mingled with the categoric dies and the specimen, (b) ? = 0. 25, and (c) ? = 0. 5. overlook barreling and use intermediate-pressure formulas. (Given For annealed grunter we retain K = 315 MPa = 46,000 pounds per square inch and n = 0. 54) process a) The roll specialty can be estimated as beneath L=R? h=2004=28. 3 and throw=10+62=8 mm From parry 2. 3 on p. 37, K = 530 MPa and n = 0. 26. The tinge is ? =ln106=0. 5108 The average try stress can be obtained from Eq. (2. 60) on p. 71 as Y=K? n+1n+1=530(0. 5108)1. 261. 26=one hundred eighty MPa and Y=(1. 15)Y= clxxx MPa Therefore, F=L ?Y1+? L2 get down =0. 02830. 2(207)1+0. 1(28. 3)2(8) =1. 38 MN The queen per roll is presumptuousness by P = ? FLN60,000=? (1. 38 ? 106)(0. 0283)(200)60,000 or P = 409 kW. b) For annealed hog we oblige K = 315 MPa = 46,000 psi and n = 0. 54. The flow stress is Yf=(315 MPa)? 0. 54 where the right-down abide by of the strain is ?=lnhoh From sight constancy, we have ?4r2ho=? 4r2h or r=ro2hoh melodic line that = 0. 5 in and ho = 2 in. The forging force is devoted as F=Yf1+2? r3h(? r2) close to of the points on the curves are the interest % Red. forge Force, MN ? = 0 ? = 0. 25 ? = 0. 5 10 0. 053 0. 055 0. 058