Rotary Friction Welding of Dissimilar Joints between SSM356 and SSM6061 Aluminium Alloys Produced by GISS

The objective of research is to investigate the parameters, microstructure and mechanical properties of butt joint SSM356 with SSM6061 aluminum alloy by using RFW processes. The main parameters for rotation speeds are 1550, 1700 and 1850 rpm and for burn of length are 2, 2.5 and 3 mm respectively. After experiment, we found that both materials showed strong weld ability although it has a different chemical composition. The microstructural changes in welded metals caused deformation leading to smaller particle sizes. The average Mg2Si particle size was at 0.998 µm long and the width of this particle was at 1.021 µm when it was rotated at 1850 rpm with burn of length at 2.5 mm. The maximum average tensile strength is 87.24 MPa, efficiency of the weld joints is 51.89 percent compared with the base metal of SSM356 aluminum alloys (base metal is 168.12 MPa), and efficiency of the weld joints is 68.45 percent compared with the base metal of SSM6061 aluminum alloys (base metal is 127.44 MPa). Besides, the small particle distribution in the welded metal promotes the hardness property increasing up to 65.56 HV.