Study on the thermal-assisted underwater friction stir lap welding for thermoplastic PC

In this paper, the heat-assisted underwater friction stir welding (UFSW) lap test of thermoplastic polycarbonate (PC) sheets is studied. The contribution of rotational speed, welding speed and water temperature to the tensile strength of welds is analyzed by the Taguchi experiment and analysis of variance (ANOVA). The results indicate that the welding speed has the greatest effect on the tensile strength, followed by water temperature and finally rotation speed. The welding surface appearance and fracture surfaces confirm that the best parameter of UFSW of PC is the rotation speed of 1800 rpm, welding speed of 10 mm/min and assisted water temperature of 65℃.