摘要
研究了Al-Mg-Mn-Er-Zr合金薄板及其激光焊接接头的静态拉伸性能和疲劳性能,并获得相应的S-N曲线及条件疲劳极限.通过微观组织分析及疲劳断口观察,探讨了Al-Mg-Mn-Er-Zr合金激光焊接接头的疲劳断裂原因.结果表明,Al-Mg-Mn-Er-Zr合金激光焊接接头存在明显的组织不均匀性,母材为典型的轧制组织,焊缝区的显微组织为细小等轴晶,晶粒尺寸约为40μm,热影响区为再结晶组织;激光焊接接头的抗拉强度低于母材,存在焊接接头软化的现象,接头系数约为0.73;激光焊接接头的条件疲劳极限为母材合金的68.5%;焊接接头的组织不均匀性及焊缝中的第二相夹杂是影响接头疲劳性能的主要原因.
Tensile and fatigue properties of Al-Mg-Mn-Zr-Er alloy and its laser welded joints were investigated,and the corresponded S-N curves and conditional fatigue limits were obtained.The microstructure and fatigue fracture were observed to explore the main causes of fatigue failure of Al-Mg-Mn-Zr-Er alloy laser welded joint.The results show that the microstructure of the joint was inhomogeneous.The base metal consisted of typical rolled structures,but the fusion zone mainly comprised small equiaxed grains with a size of 40 μm,and the heat-affected zone was recrystallized microstructure.The tensile strength of the welded joints was lower than that of base metal,and the joint strength coefficient was 0.73.The conditional fatigue limits of the welded joint was 68.5% of that of the base metal,and the main influence of fatigue performance were the microstructure inhomogeneity in the joint and the second phase inclusions in the weld.
出处
《焊接学报》
EI
CAS
CSCD
北大核心
2013年第6期41-44,115,共4页
Transactions of The China Welding Institution
基金
国家863高科技研究发展计划资助项目(2009AA03Z516)
关键词
含铒铝合金
激光焊接
疲劳
Er-containing aluminum alloy
laser welding
fatigue life
