Towards Qualification of Friction Stir Welding to AA5083-O and AA5052-O Aluminum Alloys

Friction Stir Welding (FSW) is an excellent alternative for joining dissimilar and similar materials in comparison to conventional welding processes. In this sense, this work aims at qualifying FSW to similar AA5083-O and AA5052-O aluminum alloys, with 6.35 mm thickness, in a CNC machining center. Therefore, four welding experiments were undertaken. At first, two types of plate surface finish were considered before joining. Afterward, two tool probe geometries, and changes in the base material position were evaluated. Hence, the welds were mainly analyzed by metallography, tensile testing, and bending tests. Results showed that the machining step to oxides removal and plates alignment is beneficial for the weld processing and the factor that has significant influence to achieve suitable joints is the tool probe geometry. Finally, by obtaining an average ultimate tensile strength (UTS) of around 191 MPa, enhanced microhardness, and bent angle of approximately 150°, the best joint was chosen.

搅拌摩擦焊（Friction Stir Welding, FSW）相较于传统焊接工艺，是实现同种及异种材料连接的优质替代方案。在此背景下，本研究旨在数控加工中心中，针对厚度为6.35mm的同种AA5083-O与AA5052-O铝合金，验证搅拌摩擦焊工艺的适配性。本次研究共开展四组焊接试验：首先设置两种焊接前的板材表面处理方式，随后评估两种搅拌针几何形状以及母材位置排布对焊接过程的影响。随后主要通过金相分析、拉伸试验与弯曲试验对焊缝进行性能表征。试验结果表明：去除氧化层与板材对中的预处理工序有利于焊接过程的顺利进行，而对获得优质接头起关键影响的因素为搅拌针几何形状。最终，本研究获得平均抗拉强度极限（Ultimate Tensile Strength, UTS）约191MPa、显微硬度得到提升且弯曲角度约150°的最优接头。