24上海电气技术2023,16(3)轨道交通用6005A铝合金疲劳断裂特征分析杨丽耿庆涛黄健吴海旭曲凤娇王东辉辽宁忠旺集团有限公司辽宁辽阳111003摘要：以供货状态下的轨道交通用薄壁复杂断面6005A空心铝合金型材为研究对象，在大气环境下采用轴向加载方式进行疲劳试验，采用扫描电子显微镜进行疲劳断口观察，分析6005A铝合金的疲劳断裂特征。试验结果显示，轨道交通用6005A铝合金疲劳源位置在试样加工的侧面，位于棱角附近，可能与表面铣加工刀痕有关。整个断口可以分为疲劳源区、疲劳扩展区、疲劳瞬断区三大部分。裂纹起源于试样表面，呈点源特征。疲劳扩展区可见明显放射棱线，疲劳瞬断区断面较粗糙。疲劳源区光亮、细滑。疲劳扩展区疲劳条带清晰，扩展中期条带间距较小，后期较大。疲劳瞬断区呈现韧窝特征。关键词：轨道交通；铝合金；疲劳断裂；特征；分析中图分类号：U270.4+1Abstract:Thestudyfocusesonthethin-walledcomplexsection6005Ahollowaluminumalloyprofileusedinrailtransitunderthesupplycondition.Fatiguetestwascarriedoutunderatmosphericenvironmentbyaxialloadingmethod,andthefatiguefracturewasobservedbyscanningelectronmicroscopetoanalyzethefatiguefracturecharacteristicof6005Aaluminumalloy.Thetestresultshowsthatthefatiguesourceof6005Aaluminumalloyusedinrailtransitislocatedonthesideofthesampleprocessing,neartheedge,whichmayberelatedtothecuttingmarkofsurfacemilling.Theentirefracturecanbedividedintothreepartssuchasfatiguesourcezone,fatiguepropagationzone,andfatiguetransientfracturezone.Thecrackoriginatesfromthesurfaceofthesampleandexhibitspointsourcecharacteristic.Obviousradiativeedgecanbeseeninthefatiguepropagationzone,andthecross-sectionofthefatiguetransientfracturezoneisrelativelyrough.Thefatiguesourcezoneisbrightandsmooth.Thefatiguebandinthefatiguepropagationzoneisclear,withasmallerspacingbetweenthebandsinthemiddlestageofexpansionandawiderspacinginthelaterstage.Thefatiguetransientfracturezoneexhibitsdimplecharacteristic.Keywords:RailTransit;AluminumAlloy;FatigueFracture;Characteristic;Analysis文献标志码：A文章编号：1674-540X（2023)03-024-04成型、耐腐蚀等诸多优点，被广泛应用于制造城际列1分析背景车、地铁、高速列车等轨道交通车辆车体...
