Influences of rotation speed mechanical properties of dissimilar joint between SSM7075 with SSM356 by friction welding

Abstract

The objective of this research is to study how rotation speeds affect mechanical properties with friction welding between semi-solid metal 7075 aluminum alloys and semi-solid metal 356 aluminum alloys. The factor of interest is rotation speeds, with different conditions at 800, 1000, 1200, 1400, and 1600 rpm respectively. 1.8 millimeter for burn of length, 30 seconds for welding time and clockwise rotation are set as a control constant condition for the entire experiment. After friction welding, we found that different rotation speeds significantly affected mechanical properties of these alloys. At rotation speed 1400 rpm, the maximum tensile strength is 122.24 MPa and the maximum hardness in welded zone is 140.5 HV. The microstructure size is 2.250 µm long and 2.144 µm wide. Its size in welded zone is practically small because of friction force. Moreover, this friction force causes the mixture of MgZn2 and Mg2Si in welded zone.