Investigation on the Effect of Torch Angle on the Formability of AA5052 CMT Weldments

Abstract

Among the various welding technologies currently available, cold metal transfer (CMT) welding process is widely used to weld sheets of Al alloys in marine and automotive fields, which provides low heat input, less distortion and reduced alteration of the base material properties compared to the traditional gas metal arc welding process. This paper focuses on weldability and formability studies on AA5052 weldments using CMT process with three different torch angles. The torch angles selected for the study are push angle (PA) of 10°, zero degree angle from vertical or 90° and drag angle (DA) of 10°. The macrostructure, microstructure, mechanical properties and forming limit diagram of the welded blanks are studied for each torch angle, and the results are compared with the base metal. The formability of welded sheets is investigated by obtaining a forming limit diagram using Nakajima test with different blank widths. Of the three angles, the welded blanks made with PA of 10° yield better tensile properties and DA has improved forming limit compared with other torch angles.