鄄T铝合金搅拌摩擦焊接头疲劳性能北京工业大学学报.PDF

第41卷 第11期 北 京 工 业 大 学 学 报 Vol.41 No.11 2015年 11月 JOURNAL OF BEIJING UNIVERSITY OFTECHNOLOGY Nov. 2015 2219鄄T6 铝合金搅拌摩擦焊接头疲劳性能 孙国芹,陈亚静,曹方莉,牛江佩,陈树君 (北京工业大学 机械工程与应用电子技术学院,北京摇 100124) 摘摇 要:为了探讨2219鄄T6铝合金搅拌摩擦焊接头疲劳断裂位置与区域局部力学性能及材料微观结构之间的关 系,对铝合金2219鄄T6搅拌摩擦焊接头开展了疲劳试验研究. 试样接头疲劳断裂处大多位于焊核区与热机区交界 处及临近区域,在裂纹萌生处的亚表面发现有大的夹杂. 焊核区有明显微空洞,小角度晶界最多. 利用ABAQUS软 件数值模拟接头疲劳,分析了接头局部区域力学性能. 接头的热机区和焊核区的主应变值较大,这些区域较其他区 域更易萌生疲劳裂纹. 关键词:搅拌摩擦焊;接头;疲劳断裂;数值模拟 中图分类号:TG405 文献标志码:A 文章编号:0254-0037(2015)11-1670-05 doi:10.11936/ bjutxb2015050054 Fatigue Property Research of Friction Stir Welded Joints for 2219鄄T6 Aluminum Alloy SUN Guo鄄qin,CHEN Ya鄄jing,CAO Fang鄄li,NIUJiang鄄pei,CHEN Shu鄄jun (College of Mechanical Engineering and Applied ElectronicsTechnology,Beijing University of Technology,Beijing 100124,China) Abstract:Fatigue tests were performed on the friction stir welded joints of 2219鄄T6 aluminum alloy in order to research the relationship between the locations of fatigue fracture of 2219鄄T6 aluminum alloy friction stir weldedjointsand local mechanical propertiesand microstructure. Thefracture locationswere mostly in thejunction of the nugget and the thermal mechanical affected zones and adjacent areas. Big impurities were foundinthesubsurfaceofthelocationofthecrackinitiation. Theobviousmicro鄄voidand the maximum amount of low angle grain boundary were found in the nugget. In order to obtain the local mechanical properties of theweldedjoints,the numerical simulation underfatigue loadingfor thewelded jointswas conducted with ABAQUS software. The result shows that principal strain values in thermo鄄 mechanical and nugget zones are bigger than that in other zones. It easily initiates