资源描述：
《毕业论文外文翻译-微孔的加工方法》由会员上传分享，免费在线阅读，更多相关内容在学术论文-天天文库。
1、大连交通大学2010届本科生毕业设计（论文）外文翻译外文原文Optionsformicro-holemakingAsinthemacroscale-machiningworld,holemakingisoneofthemost—ifnotthemost—frequentlyperformedoperationsformicromachining.Manyoptionsexistforhowthoseholesarecreated.Eachhasitsadvantagesandlimitations,dependingonth
2、erequiredholediameteranddepth,workpiecematerialandequipmentrequirements.Thisarticlecoversholemakingwiththrough-coolantdrillsandthosewithoutcoolantholes,plungemilling,microdrillingusingsinkerEDMsandlaserdrilling.HelpfulHolesGettingcoolanttothedrilltipwhilethetoolisc
3、uttinghelpsreducetheamountofheatatthetool/workpieceinterfaceandevacuatechipsregardlessofholediameter.Butthrough-coolantcapabilityisespeciallyhelpfulwhendeep-holemicrodrillingbecausethetoolsaredelicateandpronetofailurewhenexperiencingrecuttingofchips,chippackingandt
4、oomuchexposuretocarbide’sworstenemy—heat.Whenapplyingfloodcoolant,thedrillitselfblocksaccesstothecuttingaction.“Somewhereabout3to5diametersdeep,thecoolanthastroublegettingdowntothetip,”saidJeffDavis,vicepresidentofengineeringforHarveyToolCo.,Rowley,Mass.“Itbecomesw
5、isetouseacoolant-feddrillatthatpoint.”Inaddition,floodcoolantcancausemoreharmthangoodwhenmicroholemaking.“Thepressurefromthefloodcoolantcansometimessnapfragiledrillsastheyenterthepart,”Davissaid.Thetoolmakeroffersalineofthrough-coolantdrillswithdiametersfrom0.039"t
6、o0.125"thatareabletoproduceholesupto12diametersdeep,aswellasmicrodrillswithoutcoolantholesfrom0.002"to0.020".Havingthrough-coolantcapacityisn’tenough,though.Coolantneedstoflowataratethatenablesittoclearthechipsoutofthehole.Davisrecommends,ataminimum,600to800psiofco
7、olantpressure.“Itworksmuchbetterifyouhavehigherpressurethanthat,”headded.Topreventthosetinycoolantholesfrombecomingcloggedwithdebris,Davisalsorecommendsa5μmorfinercoolantfilter.Anotherrecommendationistomachineapilot,orguide,holetopreventthetoolfromwanderingontopoft
8、heworkpieceandaidinproducingastraighthole.Whenapplyingapilotdrill,it’simportanttoselectonewithanincludedangleonitspointthat’sequaltoorlargerthant
