LY12铝合金回填式搅拌摩擦点焊工艺研究

Research on Backfilling Friction Stir Spot Welding of LY12 Al Alloy

采用回填式搅拌摩擦点焊对1mm厚的LY12铝合金薄板进行焊接,研究单参数对接头拉剪力的影响。结果表明,在其他条件不变时,套下压时间影响接头U型区域的宽度,套下压时间为3.2s时,接头的拉剪力达到最大值;其他参数对U型区域深度产生影响;回填时间为0.4s、旋转速度为1500r/min、下压深度为1.1mm、焊接压力为23MPa时接头的拉剪力均达到最大值。正交试验工艺优化结果表明,最佳的工艺参数组合为:套下压时间为3.6s、回填时间为0.9 s、旋转速度为2400 r/min、下压深度为1.1 mm、压力为24 MPa。对最佳参数组合下的接头进行金相分析,发现接头区域分为三个部分:混合区、热影响区和母材。

The backfilling friction stir spot welding to weld 1 mm-thick LY12 aluminum alloy plate was adopted, and the single parameter on the effect of joint＇s shear load was investigated. The results show that when other conditions remain unchange, pressure time afl＇ect the width of the joint area. When pressure time is 3.2 s, joint＇s shear load reach maximum; other parameters affect the depth of the joint area; when refilling time is 0.4 s, rotating speed is 1500 r/min, depth is l. 1 mm, pressure is 23 MPa, joint＇s shear load reaches maximum. After the optimization of process parameters, the orthogonal test results show that the best process parameter combination is pressure time 3.6s, refilling time 0.9 s, rotating speed 2400 r/m, depth 1.1 mm, pressure 24 MPa. The metallographic analysis of the welded joint at the best parameters found that the joint area is divided into three parts： mixed zone, heat affected zone and mother material.