MECHENG 3C03 Final: 3c03.docx

• School: McMaster University
• Department: Mechanical Engineering
• Course: MECHENG 3C03
• Professor: Eu- Gene Ng

Document Summary

Temperature rise in deformation zone neglected; workpiece is rigid plastic & not affected by strain rate,strain. :areas of greater thickness that reduce cooling rate,function of part geometry;parts that have ribs may. Shear angle adjusts to give minimum work, cutting force(fp); friction angle b is constant; workpeice material isotropic;tool sharp; Merchant circle velocity discontinuity; deformation takes place in narrow zone. Limitations:works well with plastic;not with ferrous,steel. frictional force on tools rake face(fc),normal (nc),feedffq),cuttingf(fp),shearf to shearplane(fs),normalf(ns). Lee and shaffer hardening. limitaions:works only with +ve rake angle,cant have high b outcome is ve shear angle(not possible). %heat into ship(r1),heat generated/time(q1),width of cut(b),undeformed chip thickness(t),mass flow rate(mo),thermaldiffusivity( ), temp of chip leaving primary shear zone( s),temp of workpiece( w) Allowance- intentional difference b/w 2 mating parts. tolerence: permissible deviation-bilateral(+/-);unilateral(+or-);limits(maz,min dimension),geom 3classes of fits-clearance,transitions,interference. testing-evaluate product quality,performance, alter design,specs to ease manufacturing. Don"t sacrifice performance,reliability,functionality. inspection-ensure product,attributes:user gages(yes/no,shorter time for inspection,low cost product)& variables(use instruments,report dimensions,fix errors,time consuming,high cost product)material selection- envpollution,recycle,energy,geopolitical, health safety, economics,efficiency,serviceability. geometric concerns:size,precision,finish,tolerance,shape.