航空用高强高韧铝合金疲劳断口特征的研究  

Study on Fatigue Fractography of High Strength and Toughness Aluminum Alloy for Aviation

作　　者：蹇海根[1] 姜锋[1] 郑秀媛[1] 韦莉莉[1] 黄宏锋[1] 文康[1] 

机构地区：[1]中南大学材料科学与工程学院,长沙410083

出　　处：《航空材料学报》2010年第4期97-102,共6页Journal of Aeronautical Materials

基　　金：湖南省国际合作项目(2008WK3052)

摘　　要：采用金相显微镜、扫描电镜及能谱分析对T7451状态7B04铝合金疲劳断口进行了研究,揭示了该合金疲劳裂纹萌生与扩展的微观特征。合金的疲劳断口可明显划分为疲劳裂纹源区、裂纹稳定扩展区及瞬断区三个区域：疲劳裂纹从材料夹杂（大小约为（7～10）μm×（11～14）μm的富铁脆性金属间化合物粒子）处萌生,在样品表面或近表面区域形成后呈放射状扩展;疲劳裂纹扩展区可以观察到疲劳破坏的一些典型特征;瞬断区的断口形貌跟静载断裂相似,形成不平坦的粗糙表面。The fatigue fractography of 7B04-T7451 aluminum alloy was investigated by means of optical microscopy（OM）,scanning electron microscope（SEM） and energy dispersive spectrometer（EDS）.The micrographics show that the fracture surface is mainly divided into three zones such as the crack initiation,steady crack propagation and instantaneous fracture.Fatigue cracks mainly initiated at the Fe-rich intermetallic particles,which are about（7～10）μm×（11～14）μm in size and located at or near the specimen free surfaces.It also shows that fatigue cracks propagate radially.Some classical features exist in the fatigue propagation zone.The fracture morphology of the instantaneous fracture zone is similar to the one at static loading,which form a rough and uneven surface.

关 键 词：7B04铝合金 疲劳断口 疲劳裂纹萌生 疲劳裂纹扩展 

分 类 号：TG166.3[金属学及工艺—热处理] TG111.8[金属学及工艺—金属学]