摘要
通过疲劳寿命试验、断口和金相组织观察,研究了2219铝合金搅拌摩擦焊接头的疲劳断裂特征,分析讨论了搅拌摩擦焊焊接过程中产生的焊缝根部"吻接"缺陷对其疲劳性能的影响。结果表明,焊缝根部"吻接"缺陷是影响搅拌摩擦焊接头疲劳行为的主要因素。无"吻接"缺陷试样断裂于焊缝前进边侧,疲劳裂纹起源于焊缝底部,接头具有较高疲劳寿命;有"吻接"缺陷试样断裂于焊核中心,疲劳裂纹起源于"吻接"处,接头疲劳寿命较短。
Through the fatigue test,microstructure and fracture characteristics analysis,the fatigue fracture characteristic of the friction stir welded joint of the 2219 aluminum alloy was studied,and the effect of the root flaw ＂kissing-bonds＂ defect on the fatigue properties was discussed.The results show that the root flaw ＂kissing-bonds＂ defect is major factor of affecting friction stir welding fatigue behavior.The sample without＂kissing-bonds＂ defect in the advanced side fractured at the bottom weld and had long fatigue life. The sample with ＂kissing - bonds＂ defect fractured in the center of the weld, and the fatigue crack started at the ＂kissing - bonds＂ defect. The spacing of the fatigue striation reflected the fatigue life.
出处
《失效分析与预防》
2007年第3期20-24,共5页
Failure Analysis and Prevention
基金
江西省科技厅工业发展项目(BC200201014)
关键词
铝合金
搅拌摩擦焊
疲劳
“吻接”缺陷
aluminum alloy
friction stir welds
fatigue
“kissing-bonds” defect
