钛合金与铝合金复合接头的搅拌摩擦焊

为了避免搅拌头轴肩磨损及防止根部未焊透工艺缺陷,设计一种Ti/Al复合式接头,采用组合式搅拌头偏置扎入TC4钛合金与5A06铝合金对接界面进行焊接,研究其搅拌摩擦焊(FSW)工艺及组织性能. 在最佳FSW工艺条件下,完成对Ti/Al异种接头的组织结构及机械拉伸性能分析. 结果表明,接头拉伸强度达到铝合金母材强度的88.3%,断裂主要发生在铝侧焊核区内. 根据对接界面的形貌特征分析,重点讨论了Ti/Al对接界面的形成机制,认为采用较低的搅拌头转速和较小的搅拌针钛侧偏置量,可获得焊接质量较高的Ti/AlFSW接头.

Dissimilar fiction stir welding of titanium alloy and aluminum alloy employing a modified butt joint configuration

The present research employed a modified butt joint configuration into the FSW of TC4 titanium alloy and 5A06 aluminum alloy with an excess pin offset setup towards titanium alloy butt side, aiming to reduce the tool shoulder attrition, avoid butt root flaws, and study the effects of the process variables on the weld interfaces and tensile properties. Under the best FSW process condition, the examinations and analyses of macro/micro-structures, mechanical tensile properties of the dissimilar joints were conducted. The experiment results show that the joint mechanical tensile strength can reach 88.3 % of the parent aluminum alloy strength,and the tensile fracture path mainly within the stir nugget zone at aluminum alloy butt side. The formation mechanisms of the Ti/Al butt-welded interface structures were detailed according to the analyses of the characteristics at the butt interface. A high-quality Ti/Al FSW butt joint could be obtained when lower tool rotating speed and lower pin-offset value towards titanium alloy butt side were used.