搅拌摩擦焊接工艺参数和搅拌头外形尺寸对3003-H18铝合金和低碳钢焊接性能的影响

摘要

采用搅拌摩擦焊工艺对3 mm厚3003-H18铝合金和低碳钢板进行焊接，获得了无缺陷的对接焊接头。对一个适用于同种金属搅拌摩擦焊的热量输入模型进行简化，以用来研究异种金属搅拌摩擦焊接速度、旋转速度和搅拌头轴肩直径对焊接组织和性能的影响。对焊接组织、金属间化合物和接头强度的比较表明，实验结果与通过简化模型计算得到的热量输入因子(HIF)吻合较好。当HIF值介于0.2~0.4之间时，焊接接头强度受Al/Fe界面的控制；当HIF值介于0.4~0.8之间时，其强度受铝热力学影响区强度的控制；当HIF>0.8时，其强度受金属间化合物或缺陷的控制。%Defect-free butt joints of 3003 Al alloy to mild steel plates with 3 mm thickness were performed using friction stir welding (FSW). A heat input model reported for similar FSW was simplified and used to investigate the effects of welding speed, rotation speed and tool shoulder diameter on the microstructure and properties of dissimilar welds. The comparison between microstructure, intermetallics and strength of welds shows the good conformity between the results and the calculated heat input factor (HIF) achieved from the model. The joint strength is controlled by Al/Fe interface at HIF of 0.2−0.4, by TMAZ at HIF of 0.4−0.8 and by intermetallics and/or defects at HIF>0.8.