5052铝合金单搭自冲铆接头微动疲劳损伤机理研究  

Mechanism of Fretting Fatigue Damage on Single-lap Self-piercing Riveted Joints of 5052 Aluminum Alloy

作　　者：赵伦[1] 何晓聪[1] 卢毅[1] 王医锋 

机构地区：[1]昆明理工大学机电工程学院,云南昆明650500

出　　处：《热加工工艺》2016年第5期16-19,共4页Hot Working Technology

基　　金：国家自然科学基金资助项目(50965009);昆明理工大学分析测试基金项目(20140973);国家留学基金委项目(201500090194)

摘　　要：采用5052铝合金单搭自冲铆接头进行疲劳试验,研究了微动疲劳损伤对单搭自冲铆接头疲劳寿命的影响。并运用扫描电镜和能谱仪对接头微动损伤区域进行了微观分析,研究了接头微动疲劳损伤机理。结果表明:在应力比为0.1、最大疲劳载荷为接头拉剪强度的80%时,接头疲劳寿命为36826次;最大疲劳载荷为接头拉剪强度的30%时,达到疲劳寿命极限200万次。接头疲劳寿命与其微动疲劳损伤程度有关,微动疲劳损伤会减弱接头的疲劳寿命。接头疲劳失效形式主要为下板沿铆钉扣处断裂,断裂方向与加载方向垂直。接头微动疲劳损伤过程可分为微动损伤阶段和微动疲劳阶段。在微动损伤阶段,微动磨屑在接头微动接触面不断产生。在微动疲劳阶段,脱层和微裂纹的出现导致接头失效。Fatigue experiments were done with single-lap self-piercing riveted joints of 5052 aluminum alloy. The influence of fretting fatigue damage on fatigue life of the joints was studied. Fretting damage area of the joints was analyzed by using scanning electron microscope and energy spectrometer. Fretting fatigue mechanism of the joints was investigated. The results show that when stress ratio is 0.1, and the maximum fatigue load is 80% of tensile-shear load, fatigue life of joints is36826 times. When stress ratio is 0.1, and the maximum fatigue load is 30% of tensile-shear load, fatigue life of the joint is 2million times. Fatigue life of the joints is related to its fretting fatigue damage degree. Fretting fatigue damage will weaken fatigue life of the joint. Main fatigue failure mode of the joints is the bottom sheet fracture along button, and the direction of fracture is perpendicular to the load direction. The process of fretting fatigue damage joints can be divided into the stages of fretting damage and fretting fatigue. Fretting wear debris in the joint fretting contact surface continuously produces in the stage of fretting damage. Delaminating and micro-cracks generate in the stage of fretting fatigue, which leads to joint failure.

关 键 词：5052铝合金 单搭自冲铆接头 疲劳寿命 微动疲劳 

分 类 号：TG306[金属学及工艺—金属压力加工]