轴肩压入深度对AA2024/AA2024搅拌摩擦焊接头连接质量的影响

Effects of shoulder plug depth on joining performance of AA2024/AA2024 friction stir welded joints

关键词:  铝合金  搅拌摩擦焊  拉伸性能  缺陷

Key words:  aluminum alloy  friction stirs welding  tensile strength  defect

摘要:

通过调节轴肩压入深度,研究了板厚3 mm的AA2024/AA2024搅拌摩擦焊接头连接质量的变化规律.结果表明,无轴肩压入深度时,AA2024/AA2024接头的搅拌针前进侧存在"隧道"缺陷;随着轴肩压入深度的增加,"隧道"缺陷逐渐消失,接头界面轴肩搅拌区出现氧化物夹杂缺陷(S线),并呈现先增后减的演化规律,在焊核区底部也出现S线,并呈现逐渐增大的分布规律;焊接速度100 mm/min,旋转频率为800 r/min,轴肩压入深度为0.2 mm时,3 mm厚AA2024/AA2024对接接头抗拉强度达到370MPa,断面收缩率达到3.4%.

Abstract:

By adjusting shoulder plug depth,its effects on joining performance of 3mm thick AA2024/AA2024 friction stir welded joint were studied.The results show that tunnel-type defects exists at the stirring pin advancing side in joint when the shoulder is not pressed.As the shoulder plug depth increases, the tunnel-type defects disappear and oxide defects (commonly known as S line) begin to appear.The number of oxide defects increase firstly and then decreases.S line also appears at the bottom of the weld nugget zone,and becomes gradually longer with shoulder plug depth increasing.The tensile test indicates that the highest tensile strength of AA2024/AA2024 FSW joints is 370 MPa at the welding speed of 100 mm/min,pin rotational speed of 800 r/min and the shoulder plug depth of 0.2 mm,and the highest reduction of area is 3.4%.