预览加载中,请您耐心等待几秒...
1/3
2/3
3/3

在线预览结束,喜欢就下载吧,查找使用更方便

如果您无法下载资料,请参考说明:

1、部分资料下载需要金币,请确保您的账户上有足够的金币

2、已购买过的文档,再次下载不重复扣费

3、资料包下载后请先用软件解压,在使用对应软件打开

冷挤压凸模的断裂失效分析 Title:FailureAnalysisofColdExtrusionDies Introduction: Coldextrusionisacommonmethodusedinvariousindustriesforshapingmetalpartswithhighprecisionandmechanicalstrength.Thedieusedincoldextrusionplaysacriticalroleinmaintainingtheshapeandintegrityoftheextrudedworkpiece.However,thefailureofcoldextrusiondiescanleadtodisruptionsinproductionandcostlyrepairs.Thispaperaimstoanalyzethefracturefailureofcoldextrusiondiesanddiscussthepossiblecausesandpreventivemeasures. 1.FractureTypesinColdExtrusionDies: 1.1.DuctileFracture: Ductilefractureisacommonfailuremodeobservedincoldextrusiondies.Thistypeoffractureischaracterizedbyplasticdeformationbeforethecrackpropagates.Ittypicallyoccursinmaterialswithhighductility,suchasnonferrousmetalsorlow-carbonsteels.Ductilefractureiscausedbyexcessiveappliedforces,improperdiedesign,orinadequatediematerialstrength. 1.2.BrittleFracture: Brittlefractureoccurswithoutappreciableplasticdeformationpriortofailure.Itiscommonincoldextrusiondieswithhighcarbonortoolsteels.Thistypeoffracturecanbeattributedtofactorssuchasexcessivehardness,lowtoughness,andstressconcentrationcausedbydefectsordesignflawsinthedie. 2.CausesofFractureFailure: 2.1.FatigueFailure: Repeatedloadingandunloadingcyclesduringthecoldextrusionprocesscancausefatiguefailureinthedie.Thisisparticularlytruewhenthedieexperienceshighappliedstressesandstrainrates.Factorssuchasinadequatediedesign,improperheattreatment,andmaterialdefectscanacceleratethefatigueprocess,leadingtocrackinitiationandpropagation. 2.2.OverloadFailure: Excessiveappliedforcesbeyondthedie'sloadcapacitycanresultinoverloadfailure.Thiscanoccurduetofactorssuchasimproperdiedesign,incorrectmaterialselection,orunforeseenprocessvariations.Overloadfailureischaracterizedbysuddenfractureinitiationandrapidcrackpropagation. 2.3.ThermalFatigueFailure: Duringcoldextrusion,thediemayexperiencerapidheatingandcoolingcyclesduetothecontactwithhotworkpiecematerial.Thiscanresultinthermalfatiguefailure,asthedieexpandsandcontractsrepeatedly,ind