【作者】 李仲华； 袁鸽成； 朱振华； 路浩东； 曾国勋；

【Author】 LI Zhong-hua,YUAN Ge-cheng,ZHU Zhen-hua,LU Hao-dong,ZENG Guo-xun (Faculty of Materials and Energy,Guangdong University of Technology,Guangzhou 510006,China)

【机构】 广东工业大学材料与能源学院；

【摘要】 在搅拌转速为250～1400r/min范围内,采用搅拌摩擦焊焊接了5083铝合金壁板,当转速低于700r/min和高于1000r/min时,焊缝均产生不同类型的缺陷.通过肉眼、光学显微镜(OM)、扫描电子显微镜(SEM)及拉伸试验机研究了带缺陷焊缝的摩擦面和横截面形貌、力学性能及断口形貌,从热量输人和材料流动两方面分析了缺陷的成因.结果表明,转速低于700r/min时,焊缝易产生吻接缺陷,其拉伸断口呈现沿"吻接线"的分层断裂形貌;高于1000r/min时,焊缝易形成飞边及隧道缺陷,其拉伸断口呈现包含孔洞缺陷的断裂形貌;带缺陷焊缝的力学性能明显降低.热量不足或过高是形成焊缝缺陷的本质原因.更多还原

【Abstract】 In the range of rotation from 250 to 1400rpm,friction stir welding(FSW)is conducted for 5083- H321 aluminum alloy plates.As the rotation is lower than 700rpm or higher than 1000rpm,some types of defects generated easily in the welds.The microstructure of friction surface and transverse section,mechanical properties and fracture morphology of the joints with defects were investigated by using naked eye,OM,SEM.The reasons of defects are analyzed from heat input and material flow.The results show that the welds are prone to kissing bond as lower than 700rpm,and the rupture happens along the kissing bond line.However,the welds are prone to flash and tunnel defects as higher than 1000rpm,and the fracture surface shows the voids morphology caused by tunnel.The mechanical properties decrease severely by the defects.The improper heat input is the substantial reason of defects formation.更多还原