旋转速度对复合搅拌摩擦点焊接头成形及抗剪力的影响

Influence of Rotary Speed on Formation and Shearing Resistance of Al-alloy Joint in Friction Stir Spot Welding with Com-stir^(TM)

采用复合搅拌摩擦点焊的方法对2mm LF21铝合金薄板进行焊接,测试了不同旋转速度下的焊接接头的抗剪力,并观察和分析了点焊接头的成形及微观组织。结果表明:当其他参数一定时,接头的抗剪力在旋转速度为1200 r/m in时达到最大值3.47 kN,同时得到表面光亮、成形美观的焊点;显微试验结果表明复合搅拌摩擦点焊接头塑性环区和热机械影响区均发生了强烈的金属塑性流动,其中塑性环区的晶粒尺寸细小、组织致密。

The friction stir spot welding with com-stir^TM is adopted to make lap joints on the thin aluminum alloy board LF21 with a thickness of 2 mm. The shearing resistance was tested at different rotary speeds. The formation and the microstructure were observed and analyzed. Experimental results show that when the rotary speed reaches 1200 r/min, the maximum shearing resistance of the joint can be realized, about 3. 47 kN, if other parameters remain constant. At the same time, the joint surface will be bright and beautiful at this rotary speed. The metallographic structure shows that the metal flows intensively in the stirred zone and the TMAZ area, in which the grain size is minute and the structure is compact.