Influence of rotational speed on materials flow during semi-solid stirring joining of SiCp/A356 composites

A new process of vacuum-free semi-solid stirring joining on SiCp/A356 composites was investigated. The physical model and mathematical model of fixed-point stirring experiment were developed to study the influence of rotational speed to the mechanical effect of materials flow during semi-solid stirring joining. Numerical simulation and experimental results showed that the rotation of stirrer can induce an alternating pressure effect on the interface between the semi-solid filler metal and the aluminium-matrix composites. A larger rotation speed of stirrer will increase the convection of semi-solid filler metal, and exert larger pressure and wall shear stress towards the joining interface, further increase the extrusion and crushing effects to surface oxide film on the brazing side, and make it conducive to removal of oxide film, increase the forming rate of the interface.