Effect of Stirring Pin Rotation Speed on Microstructure and Mechanical Properties of 2A14-T4 Alloy T-Joints Produced by Stationary Shoulder Friction Stir Welding

Materials

Xinxin Xu¹  Huihui Zhao²  Li Zhou³  Hongyun Zhao³  Huijie Liu³  Haifeng Yang³ 

[1] Shandong Provincial Key Laboratory of Special Welding Technology, Harbin Institute of Technology, Weihai 264209, China;Shanghai Aerospace Equipments Manufacturer Co., Ltd., Shanghai 200245, China;State Key Laboratory of Advanced Welding and Joining, Harbin Institute of Technology, Harbin 150001, China;

关键词: 2A14-T4 aluminum alloy;    SSFSW;    T-joint;    microstructure;    mechanical properties;   

DOI  :  10.3390/ma14081938

来源: DOAJ

【 摘 要 】

In this study, 2A14-T4 Al-alloy T-joints were prepared via stationary shoulder friction stir welding (SSFSW) technology where the stirring pin’s rotation speed was set as different values. In combination with the numerical simulation results, the macro-forming, microstructure, and mechanical properties of the joints under different welding conditions were analyzed. The results show that the thermal cycle curves in the SSFSW process are featured by a steep climb and slow decreasing variation trends. As the stirring pin’s rotation speed increased, the grooves on the weld surface became more obvious. The base and rib plates exhibit W- or N-shaped hardness distribution patterns. The hardness of the weld nugget zone (WNZ) was high but was lower than that of the base material. The second weld’s annealing effect contributed to the precipitation and coarsening of the precipitated phase in the first weld nugget zone (WNZ1). The hardness of the heat affect zone (HAZ) in the vicinity of the thermo-mechanically affected zone (TMAZ) dropped to the minimum. As the stirring pin's rotation speed increased, the tensile strengths of the base and rib plates first increased and then dropped. The base and rib plates exhibited ductile and brittle/ductile fracture patterns, respectively.

【 授权许可】

Unknown