焊接参数对异种铝合金搅拌摩擦焊公差容限的影响

Effects of Welding Parameters on Tolerance in Friction Stir Weldingof Dissimilar Aluminum Alloys

为了研究焊接参数对异种铝合金搅拌摩擦焊公差容限的影响,采用显微硬度测试、拉伸力学性能测试、扫描电子显微镜(SEM)等分析测试手段研究了不同焊接工艺参数下的A356与AA6061异种铝合金搅拌摩擦焊焊接头的力学性能及组织。结果表明,工件间隙从0 mm增至1 mm,焊接头抗拉强度显著下降,并产生肉眼可见的焊接缺陷;搅拌头规格保持不变,将焊接速度从120 mm/min降至80 mm/min,可促进材料流动从而提高对工件间隙的容限;搅拌针直径从4 mm增至6 mm,可提高焊接的公差容限,且材料融合程度明显提高,不再出现分层现象。

To study the effects of welding parameters on the tolerance of friction stir welding(FSW)of dissimilar aluminum alloys,the mechanical properties and structure of joint of dissimilar aluminum alloys(A356 and AA6061)by FSW under different welding parameters were studied by means of micro⁃hardness testing,tensile mechanical properties testing,scanning electron microscopy among other analytical testing means.The results show that as for the workpieces with the gap from 0 mm to 1 mm,the welded joint has tensile strength decreased significantly and presents visible welding defects.With tool pin of the same specification,the material flow can be promoted by decreasing the welding speed from 120 mm/min to 80 mm/min,thus the tolerance of workpiece gap will be greatly improved.The tool pin with diameter increased from 4 mm to 6 mm can lead to higher tolerance for welding,but also the material with a higher fusion degree and without delamination.