The Effect of Plug Rotation Speed on Micro-Structure of Nugget Zone of Friction Plug Repair Welding Joint for 6082 Aluminum Alloy

This paper carried out the friction plug repair welding of 6082 aluminum alloy keyhole defects by using the method of friction heating between shaft shoulder and base material. In addition, a well-formed friction plug welding joint was obtained at different plug rotation speeds. In order to study the influence mechanism of plug rotation speeds on the microstructure of the weld nugget zone, EBSD technology was used to analyze the grain morphology, grain size and grain boundary characteristics of the weld nugget zone under different rotation speeds of the plug rod. The results show that in the nugget zone, the grain was fine and equated crystals refinement, and there was a preferred orientation. The deformation texture components in the welded nugget zone increased with the plug rotation speed from 1600 to 2000 rpm. However, the grain size first decreased and then increased, while the components in the High-Angle Boundary first increased and then decreased.