LF21铝合金双轴肩搅拌摩擦焊组织与性能  

Microstructure and property of bobbin tools friction stir welding for LF21 aluminum sheet

作　　者：张忠科[1] 廖蕴博 王希靖[1] 王亚俊[1] 

机构地区：[1]兰州理工大学甘肃省有色金属新材料国家重点实验室,甘肃兰州730050

出　　处：《电焊机》2016年第11期26-30,共5页Electric Welding Machine

基　　金：国家自然科学基金资助项目(51265030);甘肃省自然科学基金资助项目(2014GS03264)

摘　　要：利用光学显微镜、扫面电子显微镜、显微硬度仪、拉伸试验机等方法,分析6 mm厚LF21铝合金单道对接双轴肩搅拌摩擦焊焊焊缝的微观组织、力学性能、缺陷成因。实验结果表明,转速1 200 r/min、焊接速度100 mm/min时可以获得较好的焊接性能;焊缝组织呈不完全对称的沙漏状;焊缝硬度在焊缝两侧的热影响区处发生不对称的软化,前进侧组织析出相发生了明显的长大现象;抗拉强度达到103.25 MPa,焊接强度系数为基材强度的70.4%,接头断口形貌呈典型的韧性断裂。The microstructure and mechanical properties of the bobbin tools friction stir welding joints of LF21 aluminum sheet of 6 mm in thickness were investigated by optical microscope,SEM,tensile test and hardness test. The results show that when rotating speed is 1 200 r/min and welding speed is 100 mm/min,can get welds with good qualities. The micro-hardness result shows that the joints are softened obviously in HAZ with the hardness asymmetric in advancing side（AS） of weld and retreating side（RS） of weld, with the precipitated phase of growing up obviously in AS in microstructure;the tensile strength of welds can reach 103.25 MPa which is about 70.4% of that of base metal,and joint fracture morphology is a typical ductile fracture.

关 键 词：双轴肩搅拌摩擦焊 LF21 力学性能 组织分析 

分 类 号：TG457.4[金属学及工艺—焊接]