文献类型：期刊文献

英文题名：Microstructure and Mechanical Properties of TC4 Titanium Alloy Joint Fabricated By Vortex Flow-Based Friction Stir Welding

作者：Liu, Xiaochao[1,2];Zhang, Pengyu[1];Li, Wentao[1];Ye, Tao[1];Xia, Chuanchao[1];Zhang, Tairui[1];Shi, Junmiao[3];Xie, Jilin[4];Ni, Zhonghua[1,2]

机构：[1]Southeast Univ, Sch Mech Engn, Nanjing 211189, Peoples R China;[2]Southeast Univ, Adv Ocean Inst, Nantong 226010, Peoples R China;[3]East China Univ Sci & Technol, Key Lab Pressure Syst & Safety, Minist Educ, Shanghai 200237, Peoples R China;[4]Nanchang Hangkong Univ, Jiangxi Key Lab Forming & Joining Technol Aerosp C, Nanchang 330063, Peoples R China

年份：2024

卷号：37

期号：1

外文期刊名：CHINESE JOURNAL OF MECHANICAL ENGINEERING

收录：;EI(收录号：20245117553725);WOS:【SCI-EXPANDED(收录号:WOS:001379071700002)】；

基金：Not applicable.

语种：英文

外文关键词：FSW; Microstructure; Vortex flow; Weld formation; Mechanical performance; Titanium alloy

摘要：Tool wear is a critical challenge in titanium alloy friction stir welding (FSW). Vortex flow-based FSW (VFSW) is a potential solution for this issue because the VFSW process uses a similar material to the base metal as the tool. In this study, TC4 titanium alloy was welded by VFSW for the first time. Parameter optimization of the vortex flow formation is first done, and then the weld formation and the joints' microstructure and mechanical performance are investigated at different traversing speeds. The results prove that the plunging velocity is the dominant factor in the vortex depth. A lower plunging speed is beneficial for the formation of a deeper vortex. Full penetration is achieved at traversing speeds of 50-120 mm/min at 300 r/min. At welding speed above 130 mm/min, insufficient penetration defects occur. In the heat affected zone, grain coarsening and beta-phase volume fraction increase arise, whereas, in the weld nugget, an alpha+beta lamellar structure emerges. Under the optimized parameters, the joint tensile strength is nearly 98% of the base material, but the elongation decreases significantly. The oxides drawn into the weld by the vortex at the junction between the vortex and the base material are the main reason for the small elongation. This study proves that the VFSW process is feasible for titanium alloys.