机械类、模具类外文翻译（英文+译文）

DEEPDRAWINGWITHINTERNALAIRPRESSINGTOINCREASETHELIMITDRAWINGRATIOOFALUMINUMSHEETYOUNGHOONMOONT,YONGKEEKANG,JINWOOKPARK,SUNGRAKGONGENGINEERINGRESEARCHCENTERFORNETSHAPEANDDIEMANUFACTURING,PUSANNATIONALUNIVERSITYTHEEFFECTSOFINTERNALAIRPRESSINGONDEEPDRAWABILITYAREINVESTIGATEDINTHISSTUDYTOINCREASETHEDEEPDRAWABILITYOFALUMINUMSHEETTHECONVENTIONALDEEPDRAWINGPROCESSISLIMITEDTOACERTAINLIMITDRAWINGRATIOLDRBEYONDWHICHFAILUREWILLOCCURTHEINTENTIONOFTHISWORKISTOEXAMINETHEPOSSIBILITIESOFRELAXINGTHEABOVELIMITATIONTHROUGHTHEDEEPDRAWINGWITHINTERNALAIRPRESSING,AIMINGTOWARDSAPROCESSWITHANINCREASEDDRAWINGRATIOTHEIDEAWHICHMAYLEADTOTHISGOALISTHEUSEOFSPECIALPUNCHTHATCANEXERTHIGHPRESSUREONTHEINTERNALSURFACEOFDEFORMINGSHEETDURINGTHEDEEPDRAWINGPROCESSOVERTHERANGESOFCONDITIONSINVESTIGATEDFORAI1050,THELOCALSTRAINCONCENTRATIONATPUNCHNOSERADIUSAREAWASDECREASEDBYINTERNALAIRPRESSINGOFPUNCH,ANDTHEDEEPDRAWINGWITHINTERNALAIRPRESSINGWASPROVEDTOBEVERYEFFECTIVEPROCESSFOROBTAININGHIGHERLDRKEYWORDSDEEPDRAWING,INTERNALAIRPRESSING,LIMITDRAWINGRATIOLDR,AI10501INTRODUCTIONALUMINUMALLOYSHEETSAREINFERIORINPRESSFORMABILITYCOMPAREDTOTHEMILDSTEELSHEETSMOSTOFTHEALUMINUMALLOYSHAVEANRVALUEPLASTICANISOTROPYVALUEBETWEEN07AND10NONETHELESS,EVENTHOUGHTHERVALUESFORTHEALUMINUMALLOYSAREONLYABOUTHALFOFSTEELROGER,1991,THEYSHOW,UNDERTHERIGHTCIRCUMSTANCES,QUITESATISFACTORYDRAWINGBEHAVIORAMONGTHEALUMINUMALLOYSSOMENOTICEABLEDIFFERENCESINFORMINGBEHAVIORONTHESTAMPINGSHOPFLOORHAVEBEENOBSERVEDROGER,1991LANGE,1985BECAUSETHERELATIONSHIPBETWEENTHEMATERIAL,DIEDESIGNANDTESTPARAMETERS,ETC,VERSUSTHEDEEPDRAWABILITYMAYCHANGEWITHALLOYSYSTEMSWHILEMANYOFTHEGENERALMETALLURGICALANDDIEDESIGNPRINCIPLESTHATPROMOTEENHANCEDDEEPDRAWINGAREUNDERSTOOD,THERESEARCHESTOIMPROVETHEFORMABILITYOFALUMINUMSHEETARESTILLINSUFFICIENTDEEPDRAWINGISAPROCESSFORSHAPINGFLATSHEETSINTOCUPSHAPEDARTICLESWITHOUTFRACTUREOREXCESSIVELOCALIZEDTHINNINGTFIRSTAWHORCORRESPONDINGAUTHOR,EMAILYHMOONHYOWONPUSANACKRTEL82515102472FAX82515121722ENGINEERINGRESEARCHCENTERFORNETSHAPEANDDIEMANUFACTURING,PUSANNATIONALUNIVERSITY,PUSAN609735,KOREAMANUSCRIPTRECEIVEDAUGUST7,2000REVISEDJANUARY30,2001THEDESIGNANDCONTROLOFADEEPDRAWINGPROCESSDEPENDSNOTONLYONTHEWORKPIECEMATERIAL,BUTALSOONTHECONDITIONATTHETOOLWORKPIECEINTERFACE,THEMECHANICSOFPLASTICDEFORMATIONANDTHEEQUIPMENTUSEDTHEEQUIPMENTANDTOOLINGPARAMETERSTHATAFFECTTHESUCCESSORFAILUREOFADEEPDRAWINGOPERATIONARETHEPUNCHANDDIERADII,THEPUNCHANDDIECLEARANCE,THEPRESSSPEED,THELUBRICATIONANDTHETYPEOFRESTRAINTTOMETALFLOWHRIVNAKANDSOBOTOBA,1992DATEANDPADMANABHAN,1992YOSSIFONANDTISOSH,1991THIRUVARUDEHELVANANDLOH,1993KAWAIETAL,1992JOHNSONANDMELLOR,1983TOESTABLISHTHEGEOMETRYOFAPARTTHATCANBESUCCESSFULLYANDECONOMICALLYFABRICATEDFROMAGIVENMATERIAL,ITISESSENTIALTOKNOWTHELIMITTOWHICHTHEPARTMATERIALCANBEFORMEDWITHOUTREACHINGFAILURETHISFORMINGLIMITDEPENDS,INADDITIONTOTHESHAPECHANGEANDPROCESSCONDITIONS,ONTHEABILITYOFAMATERIALTODEFORMWITHOUTFAILURETHELIMITINGDRAWINGRATIOLOR,ISCOMMONLYUSEDTOPROVIDEAMEASUREOFTHEDRAWABILITYOFSHEETMETAL,BEINGTHERATIOOFMAXIMUMBLANKDIAMETERTOPUNCHDIAMETERUNDERTHEDRAWINGLIMITWITHOUTFAILURETHOMASANDDADRAS,1981LEU,1997CHENANDSOWERBY,1996ITISWELLRECOGNIZEDTHATAHIGHPLASTICANISOTROPYVALUERVALUECLEARLYINDICATEDABETTERDRAWABILITY,BYINDUCINGAHIGHRESISTANCEOFASHEETTOTHINNINGBUTTHEREISNOSINGLEMATERIALPARAMETERWHICHSATISFACTORILYDESCRIBESTHEDRAWINGBEHAVIORINTHISWORK,THEEFFECTOFINTERNALPRESSINGONTHEFORMABILITYOFALUMINUMSHEETISINVESTIGATEDTOINCREASETHELOROFALUMINUMALLOYSFIGURE1ISASCHEMATICOFACUPDIE,SHOWINGTHEPUNCH,DIEANDBLANKHOLDER,ANDAPARTIALLYFORMEDCUPTHEPUNCHISONTHEDOWNSTROKEANDISJUSTBEGINNINGTODRAWTHESHEETMETALBLANKINTOTHEDIECAVITYIFTHEBLANKSIZEHASBEENCHOSENCORRECTLY,THEMETALWILLWORKHARDENSUFFICIENTLYTOOVERCOMETHECOMBINEDSTRENGTHOFTHEREMAINDEROFTHEBLANKMETALANDFRICTIONBETWEENITANDTHEBLANKHOLDERANDTHEPARTWILLBESUCCESSFULLYMADEHOWEVER,IFTHEBLANKISTOOLARGE,THEPARTWILLBREAKWHENTHETENSILESTRENGTHISEXCEEDEDTHEFIRSTDEFORMATIONOFTHEBLANKOCCURSBETWEENTHEDIERADIUSANDTHEPUNCHNOSERADIUSPART,SINCETHISISTHEPARTTHATISNOTSUPPORTEDBYFRICTIONWITHTHETOOLINGCOMPONENTSTHEMETALINTHISSECTIONISINCREASINGINAREAASITTHINSOUTANDLOSINGMUCHOFITSSTRENGTHTHEREFORE,THESTRAINCONCENTRATIONSATDIERADIUSANDPUNCHNOSERADIUSPARTHAVEBEENTHEMAINCAUSEOFEARLYFAILUREIFTHESTRAINCONCENTRATIONINTHISCRITICALAREACANBERELEASED,THELOADCARRYINGCAPACITYWILLBEINCREASEDANDBREAKAGECANBEAVOIDEDONEPOSSIBLEWAYTODOTHISISAIRPRESSINGTHEINTERNALSURFACEOFTHEBLANKBYUSINGSPECIALLYDESIGNEDPUNCHBECAUSETHEAIRPRESSINGCANREDUCETHELOCALSTRAINCONCENTRATIONANDTHUSRETARDANEARLYFAILURETHETESTMETHODSANDRESULTSAREDESCRIBEDINTHISARTICLE2EXPERIMENTALPROCEDURE21MATERIALANDEQUIPMENTCOMMERCIALLYAVAILABLEAL1050ALUMINUMSHEETWITHATHICKNESSOF10MMISUSEDFORTHEBLANKMATERIALTENSILEPROPERTYOFTHEAI1050ISSHOWNINTABLEIPRELIMINARYEXPERIMENTSSHOWTHATBLANKSWITHDIAMETERSOFLESSTHAN70MMAREDRAWNWITHOUTFAILURETHEREFOREBLANKDIAMETERSAREPROGRESSIVELYINCREASEDBYIMMFROMTHEBLANKDIAMETERSOF70MMWHENFAILUREOFBLANKOCCURS,EXPERIMENTSPROCEEDWITHTHEDIAMETERINCREASINGORDECREASINGIMMTOASCERTAINTHEMAXIMUMDIAMETEROFTHEBLANKSHEETWITHOUTFAILUREINCUPDRAWINGFORESTIMATINGTHELDRVALUEFIGURE2SHOWSTHEDEEPDRAWINGMACHINETHATISUSEDINTHISINVESTIGATIONITISAHYDRAULICPRESSWITHAMAXIMUMLOADCAPACITYOF50TONANDAVARIABLEPUNCHSPEEDOFIMM/SEC15RUM/SECINTHISPRESS,THEPUNCHISMOUNTEDONTHELOWERSHOEANDTHEDIEONTHEUPPERSHOEOFTHEMACHINETHEPUNCHINGANDBLANKHOLDINGFORCESANDTHEPUNCHSTROKECANBEMEASUREDSEPARATELYBYINDICATORSTHOSEAREPROVIDEDONTHEMACHINEPROPERTOOLSTEELWITHAPPROPRIATEMECHANICALPROPERTIESANDHARDENINGTREATMENTISUSEDFORTHEMATERIALSOFTHEPUNCHESANDDIESTHETOOLSAREGROUNDTOANAPPROPRIATESURFACEFINISHANDAFINALHARDNESSOF60HRCFIGURE3SCHEMATICALLYSHOWSPUNCHANDDIESETUSEDINTHISSTUDYFORTHEAIRPRESSING,THEPUNCHHASBEENBOREDOUTANDHIGHPRESSUREAIRLINEWASCONNECTEDTHISARRANGEMENTWASUSEDTOPRODUCEINTERNALAIRPRESSUREOFMAXIMUM110KGF/CM2THEGEOMETRYOFTHEPUNCHANDDIE,ESPECIALLYTHEIRPROFILERADII,ARETHEMAJORVARIABLESINDEEPDRAWINGPROCESSESITHASBEENSHOWN8THATFORAPUNCHNOSERADIUS,RP,THATISLESSTHANTWICETHETHICKNESSOFTHEBLANK,TO,THECUPSFAILDUETOTEARING,WHILEFORPUNCHNOSERADIUSTHATISLARGERTHAN10TOSTRETCHINGMAYBEINTRODUCEDINADDITION,WITHINTHEREGION4TORP10TOTHERADIUSDOESNOTSIGNIFICANTLYAFFECTTHELIMITINGDRAWINGRATIOLORTHEREFORE,ACCORDINGTOTHETHICKNESSOFTHEBLANK,THEMOSTSUITABLESHOULDERRADIIFORTHEDIESANDPUNCHESWERESELECTEDTOBE6MMWITHACONSTANTPUNCHDIAMETEROF386MM22TESTPROCEDUREAPROPERDRAWINGSPEEDISIMPORTANTFORTHEDEEPDRAWINGPROCESSEXCESSIVESPEEDSCANCAUSEWRINKLINGORFRACTUREINTHEFORMEDPARTANDDAMAGEOFTHETOOLINGWHILEINSUFFICIENTSPEEDSREDUCETHERATEOFPRODUCTIONINTHISINVESTIGATIONADRAWINGSPEEDOF4MM/SECISFOUNDTOBETHEMOSTSUITABLESPEEDTHEBLANKHOLDERFORCEISCHOSENTOBETHEMINIMUMFORCEREQUIREDTOPREVENTWRINKLINGOFTHELARGESTBLANKANDISFOUNDTOBE350KGFANOPERATIONSEQUENCEISARRANGEDFORTHETESTSANDTHEPUNCHFORCESAREMEASUREDSIMULTANEOUSLYASFUNCTIONOFTESTVARIABLESTHEAIRPRESSUREISAPPLIEDUNTILTHELOADREACHESTHEMAXIMUMLOADBECAUSETHEAIRPRESSINGAFTERREACHINGTHEMAXIMUMLOADNOLONGERAFFECTBETTERDEEPDRAWABILITYEACHTESTISREPEATEDTWOORTHREETIMES,AVERAGEVALUESBEINGOBTAINEDALLEXPERIMENTSWERECARRIEDOUTBYTHECUPDRAWINGOPERATIONSHOWNINFIG3ANDEXPERIMENTALVARIABLESAPPLIEDINTHISSTUDYAREDESCRIBEDINTABLE2PRESSOIL,COMMERCIALGRADEHIGHPRESSUREHYDRAULICOIL,ISBRUSHEDONTOTHEBLANKBEFOREFORMINGTODIMINISHTHEFRICTIONATTHECONTACTINTERFACETHEEFFECTIVENESSOFTHEAIRPRESSINGWASJUDGEDBYLORTHATISDETERMINEDBYTHEMAXIMUMSIZEOFBLANKTHATCOULDBEFORMEDINTOACUP,SINCETHEBLANKSIZEDETERMINESTHEMAXIMUMCUPDEPTH,ANDCANBEMEASUREDMOREACCURATELY3RESULTSANDDISCUSSIONTOINVESTIGATETHEEFFECTOFAIRPRESSINGONTHEDEEPDRAWABILITY,THELORISOBTAINEDATEACHPROCESSCONDITIONFORTHECALCULATIONOFLOR,THEMAXIMUMBLANKDIAMETER,THISDIAMETERBEINGTHATBELOWWHICHTHEBLANKSWILLBEDRAWNSUCCESSFULLYANDABOVEWHICHTEARINGWILLOCCURINTHECUPWALLISDETERMINEDFIGURE4SHOWSTHEVARIATIONOFLORWITHINCREASINGAIRPRESSUREFORAI1050ANDFIG5SHOWSPHOTOGRAPHOFDEEPDRAWNCUPSATGIVENPROCESSCONDITIONSABOVEFIGURESSHOWTHATHIGHERLORISOBTAINEDATHIGHERINTERNALAIRPRESSURETHEREASONFORTHEINCREASEDLORATHIGHERAIRPRESSURECANBEEXPLAINEDBYTHICKNESSPROFILEOFCROSSSECTIONEDCUPSHOWNINFIG6FIGURE6SHOWSTHATTHEOVERALLTHICKNESSOFDEEPDRAWNCUPANDTHEDEGREEOFTHICKNESSVARIATIONATROUNDINGPARTAREDECREASEDATTHEAIRPRESSUREOF70KG/MM,THERELATIVELYSTEEPDECREASEINTHICKNESSATROUNDINGPARTTHATHADTOUCHEDWITHPUNCHNOSERADIUSREFLECTSTHELOCALSTRAINHASBEENCONCENTRATEDONTHISPARTTHEREFORE,THEDECREASEINTHEDEGREEOFTHICKNESSVARIATIONATTHEROUNDINGPARTCONFIRMSTHATTHELOCALSTRAINCONCENTRATIONHASBEENRELAXEDBYAIRPRESSINGFIGURE7SHOWSTHEEFFECTOFTHEAIRPRESSUREONTHEDRAWINGLOADDISPLACEMENTCURVESINGENERAL,ANINCREASEINTHEDRAWINGFORCEISOBSERVEDFORLARGERBLANKDIAMETERSDUETOTHEENLARGEMENTOFFICTIONALINTERFACESSUCHASTHEDIEBLANKANDBLANKHOLDERBLANKINTERFACESWHILETHEFIGUREINDICATESTHATTHEMAXIMUMDRAWINGLOADSARENOTSOSIGNIFICANTLYINCREASEDEVENWITHINCREASINGMAXIMUMBLANKDIAMETERSATHIGHERAIRPRESSUREITMEANSTHATTHEINTERNALAIRPRESSINGCONTRIBUTETOTHEREDUCTIONOFDRAWINGLOADPOSSIBLYBYREDUCINGFRICTIONBETWEENPUNCHANDBLANKINOTHERWORDS,THEINTERNALAIRPRESSINGITSELFDOESNOTALTERTHEDEFORMATIONRESISTANCEOFDEFORMINGSHEETBLANKSBUTHASANEFFECTONTHEMANNEROFTHETRANSMISSIONOFTHELOADATPUNCHNOSERADIUSPARTANDINCREASESLOROFBLANKALTHOUGHTHEEXPERIMENTALCONDITIONSUSEDINTHISSTUDYMAYNOTBETHEOPTIMUMFORTHEHIGHESTLOR,THETRENDSOBVIOUSLYSHOWSTHATTHEINTERNALAIRPRESSINGISADVANTAGEOUSFORHIGHERLORTHEEFFECTIVENESSOFTHEAIRPRESSINGPROCESSDEPENDSONHOWWELLTHEMETALCANBEPRESSEDTHEREFORE,THEEFFECTOFAIRPRESSINGPROCESSWILLBEMOREPROMINENTFORALUMINUMALLOYSHEETSTHANMILDSTEELSHEETS4CONCLUSIONTHEAIRPRESSINGMETHODISPROVEDTOBEVERYEFFECTIVEININCREASINGTHEDEEPDRAWABILITYOFAI1050ONTHEBASISOFTHEEXPERIMENTALINVESTIGATIONMADEHEREIN,HIGHERAIRPRESSINGGUARANTEESHIGHERLDRTHEINCREASEDLDRISMAINLYCAUSEDBYTHERELAXATIONEFFECTOFLOCALSTRAINCONCENTRATIONATPUNCHNOSERADIUSAREATHERESULTSTHATHAVEBEENDESCRIBEDABOVESHOWTHATAIRPRESSINGMETHODALSOHASTHEPOTENTIALTOINCREASETHELDROFOTHERMETALALLOYSHEETSACKNOWLEDGEMENTSTHISWORKHASBEENSUPPORTEDBYTHEENGINEERINGRESEARCHCENTERFORNETSHAPEANDDIEMANUFACTURINGERC/NSDM,WHICHISFINANCEDJOINTLYBYTHEKOREANSCIENCEANDENGINEERINGFOUNDATIONKOSEFREFERENCESCHENXANDSOWERBYR,1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