Wang Yu-Shu, Lv Xue-Qi, Xia Chun-Ming, Li Xiong-Ying, Yang Jie, Li Chong-Gui
School of Materials Engineering, Shanghai University of Engineering Science, Shanghai 201620, China.
School of Mechanical and Automotive Engineering, Shanghai University of Engineering Science, Shanghai 201620, China.
Materials (Basel). 2024 Nov 27;17(23):5814. doi: 10.3390/ma17235814.
The fracture position of a friction plug welding (FPW) joint is typically located at or near the thermo-mechanically affected zone (TMAZ). Here, we found that microcracks in all FPW specimens initiate at the deformed plug center (DPC) zone and then propagate through the plug center along 45° shear surfaces, because the lowest hardness occurs at the DPC zone rather than the TMAZ or other zones, and the DPC zone presents a tilt fiber-like microstructure. Such a tilt microstructure stimulates formations and deformations of microvoids and propagation of microcracks along 45° shear surfaces. The ultimate tensile strength (237.7 MPa) and yield strength (220.8 MPa) of the FPW joint reach 78.8% and 85.7% of the base metal, respectively. These results indicate that 6061-T6 aluminum alloy can be effectively joined by the FPW technique.
摩擦塞焊（FPW）接头的断裂位置通常位于热机械影响区（TMAZ）或其附近。在此，我们发现所有FPW试样中的微裂纹均在变形塞中心（DPC）区域萌生，然后沿着45°剪切面穿过塞中心扩展，这是因为最低硬度出现在DPC区域而非TMAZ或其他区域，且DPC区域呈现出倾斜的纤维状微观结构。这种倾斜的微观结构促使微孔的形成与变形以及微裂纹沿45°剪切面扩展。FPW接头的抗拉强度（237.7MPa）和屈服强度（220.8MPa）分别达到母材的78.8%和85.7%。这些结果表明，采用FPW技术能够有效地连接6061-T6铝合金。
