铝锂合金T型自冲铆接头疲劳特性及失效机理

发布时间：2018-02-01 19:15

本文关键词： 铝锂合金 T型自冲铆接头疲劳试验 SEM扫描电镜断裂特征　出处：《材料导报》2017年12期 　论文类型：期刊论文

【摘要】：为研究T型自冲铆接头的疲劳特性,以铝锂合金(AL1420)同种及其与铜合金(H62)和不锈钢(410)异种组合制备的AA、HA和SA三组T型自冲铆接头为研究对象,基于其静力学试验采用正弦波进行拉-拉加载疲劳试验,用二参数威布尔分布对所得疲劳数据的有效性进行验证,采用最小二乘拟合直线得到拟合的F-N曲线,并采用SEM扫描电镜对各组典型疲劳失效断口进行微观分析。结果表明:SA组疲劳寿命对载荷变化最敏感,并且疲劳寿命随相对滑移量的增加而减小;由三组T型接头失效形式可看出接头薄弱环节有由铆钉向板材转移的趋势;从微观分析疲劳断口可知裂纹萌生区多为形貌特征较为平坦的准解理,裂纹瞬断区形貌更加突出,多为沿晶断裂或韧窝形貌。
[Abstract]:In order to study the fatigue characteristics of T-type self-impact riveting head, AA was prepared from Al-Li alloy (AL1420) and its combination with copper alloy (H62) and stainless steel (410). Based on the static test of HA and SA three groups of T-type self-impact riveting heads were used to carry out tensile and tensile loading fatigue tests based on their statics. The validity of the fatigue data was verified by two-parameter Weibull distribution. The fitted F-N curve was obtained by the least square fitting line, and the typical fatigue failure fracture of each group was analyzed by SEM scanning electron microscope. The results showed that the fatigue life of the 1: SA group was the most sensitive to the change of load. The fatigue life decreases with the increase of relative slip. According to the failure form of three groups of T-joints, it can be seen that the weak links of the joints have the tendency of transferring from rivets to plates. From the microscopic analysis of fatigue fracture, it can be seen that most of the crack initiation areas are quasi-cleavage with flat morphology, and the morphology of the crack transient fracture zone is more prominent, most of which are intergranular fracture or dimple morphology.
【作者单位】：昆明理工大学机电工程学院;
【基金】：国家自然科学基金(51565023;51565022) 国家科技重大专项项目(2012ZX04012-031) 云南省教育厅科学研究基金重大专项项目(ZD201504)
【分类号】：TG938
【正文快照】： 0引言随着人们对节能减排、低碳生活的要求不断提高,汽车产业发展也面临着巨大挑战,汽车车身轻量化探索亟待新突破。车身轻量化课题所面临的难关比较多,其中制约轻量化发展所遇到的瓶颈问题是新轻型材料的连接。自冲铆连接技术的发展为解决这个问题带来希望。自冲铆连接技术是

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