AZ31B挤压变形镁合金低周疲劳行为研究  

Study on the low cycle fatigue behavior of extruded AZ31B magnesium alloy

作　　者：耿长建[1] 武保林[2] 刘芳[1] 佟文伟[1] 韩振宇[1] 

机构地区：[1]中国航空工业集团公司沈阳发动机设计研究所材料应用研究室,沈阳110015 [2]沈阳航空航天大学材料科学与工程学院,沈阳110136

出　　处：《沈阳航空航天大学学报》2014年第4期44-49,共6页Journal of Shenyang Aerospace University

基　　金：国家自然科学基金(项目编号:51171120;090202001)

摘　　要：分别研究了挤压变形AZ31B镁合金在非对称载荷与对称载荷下的疲劳行为,结果表明两种加载方式下,疲劳过程随着应变幅的增加,滞回曲线的不对称性均增强;在低应变幅下,位错滑移为主要塑性变形机制;而在较高应变幅下,孪生-去孪生为主要变形机制;同一应变幅下,压-压非对称低应变幅疲劳寿命最长,拉-压对称低应变幅疲劳寿命次之,拉-拉非对称低应变幅疲劳寿命最短。The paper focuses on the low cycle fatigue behavior of AZ31B magnesium alloy under symmetric and asymmetric loading. The results show that the asymmetry of the hysteresis is enhanced with strain amplitude increasing. At lower strain amplitude, dislocation slip is the dominant plastic deformation mechanism responsible for cyclic hardening. At high strain amplitude, twinning - detwinning is the key deformation mechanism. During the cyclic fatigue, the elastic strain of the tensile process is larger than that of compressive process. At the same strain amplitude, the longest fatigue life is under incompressive - compressive asymmetric loading, followed by that under the tensile - compressive symmetric loading, and the shortest is under the tensile- tensile asymmetric loading.

关 键 词：AZ31B镁合金 滞回曲线 位错滑移 孪生-去孪生 

分 类 号：V252.2[一般工业技术—材料科学与工程]