Ahmed Mohamed M Z, El-Sayed Seleman Mohamed M, Ahmed Essam, Reyad Hagar A, Touileb Kamel, Albaijan Ibrahim
Mechanical Engineering Department, College of Engineering at Al-Kharj, Prince Sattam Bin Abdulaziz University, Al Kharj 16273, Saudi Arabia.
Department of Metallurgical and Materials Engineering, Faculty of Petroleum and Mining Engineering, Suez University, Suez 43512, Egypt.
Materials (Basel). 2022 Apr 19;15(9):2971. doi: 10.3390/ma15092971.
Friction stir spot welding (FSSW) is one of the important variants of the friction stir welding (FSW) process. FSSW has been developed mainly for automotive applications where the different thickness sheets spot welding is essential. In the present work, different thin thickness sheets (1 mm and 2 mm) of AA6082-T6 were welded using FSSW at a constant dwell time of 3 s and different rotation speeds of 400, 600, 800, and 1000 rpm. The FSSW heat input was calculated, and the temperature cycle experience during the FSSW process was recorded. Both starting materials and produced FSSW joints were investigated by macro- and microstructural investigation, a hardness test, and a tensile shear test, and the fractured surfaces were examined using a scanning electron microscope (SEM). The macro examination showed that defect-free spot joints were produced at a wide range of rotation speeds (400-1000 rpm). The microstructural results in terms of grain refining of the stir zone (SZ) of the joints show good support for the mechanical properties of FSSW joints. It was found that the best welding condition was 600 rpm for achieving different thin sheet thicknesses spot joints with the SZ hardness of 95 ± 2 HV0.5 and a tensile shear load of 4300 ± 30 N.
搅拌摩擦点焊（FSSW）是搅拌摩擦焊（FSW）工艺的重要变体之一。FSSW主要是为汽车应用而开发的，在汽车应用中，不同厚度板材的点焊至关重要。在本研究中，使用FSSW对不同厚度的AA6082-T6薄板（1毫米和2毫米）进行焊接，保压时间恒定为3秒，旋转速度分别为400、600、800和1000转/分钟。计算了FSSW的热输入，并记录了FSSW过程中的温度循环经历。通过宏观和微观结构研究、硬度测试和拉伸剪切测试对母材和所制备的FSSW接头进行了研究，并使用扫描电子显微镜（SEM）检查了断口表面。宏观检查表明，在较宽的旋转速度范围（400 - 1000转/分钟）内都能制备出无缺陷的点焊接头。接头搅拌区（SZ）晶粒细化方面的微观结构结果为FSSW接头的力学性能提供了良好的支持。结果发现，对于不同薄板厚度的点焊接头，最佳焊接条件是旋转速度为600转/分钟，此时SZ硬度为95±2 HV0.5，拉伸剪切载荷为4300±30 N。
