Study on defect in the intersection of VPPA and FSW

Abstract

In order to investigate the defects in the intersection of variable polarity plasma arc (VPPA) welding seam with the friction stir welding seam. Different kinds of specimens with crossing and overlapping welding seams were prepared. Defects in the overlapping and crossing welding seam were detected. The mechanism of defects was further explored. At last, the schematic of welding porosity forming were given.