新型Al-Zn-Mg-Cu铝合金疲劳性能及损伤断裂行为研究  

Research on fatigue performance and damage crack behavior of new style Al-Zn-Mg-Cu aluminum alloy

作　　者：刘铭[1] 汝继刚[1] 伊琳娜[1] 李惠曲[1] 王亮[1] 郝敏[1] 胡昭 

机构地区：[1]北京航空材料研究院,北京100095 [2]陕西飞机工业(集团)有限公司,陕西汉中723213

出　　处：《轻合金加工技术》2014年第7期63-69,共7页Light Alloy Fabrication Technology

摘　　要：采用旋转弯曲和轴向加载疲劳试验方法,研究了7A12铝合金的疲劳性能,并通过金相显微镜(OM)、扫描电镜(SEM)和透射电镜(TEM)分析了该合金的显微组织结构和疲劳断口特征。结果表明,7A12铝合金具有较好的疲劳性能,合金的疲劳极限随应力比的增加而增大,随应力集中系数的增加而显著降低;断口形貌具有典型的疲劳断口特征,由疲劳源区、疲劳裂纹稳定扩展区和快速断裂区三部分组成,裂纹萌生一般位于表面夹杂或缺口等缺陷引起的应力集中处。The fatigue property of 7A12 aluminum alloy was studied by fatigue test under rotating bending and axial loading. The microstructure and the fracture appearance sections were analyzed by OM, SEM and TEM. The results show that 7A12 aluminum alloy possesses the excellent fatigue performance. The fatigue limit increases with the stress ratios increasing, whereas, decreases with stress concentration factor Kt increasing. The fracture appearance has typical features of fatigue fracture, consisting of fatigue crack initiation zone, fatigue crack propagation zone and final fracture zone. Locations of the initial fatigue cracks are generally on the stress concentration point caused by inclusions or notches on the surface.

关 键 词：7A12铝合金 疲劳性能 断裂行为 断口形貌 疲劳裂纹 

分 类 号：TG146.21[一般工业技术—材料科学与工程]