COMPARISON STUDY ON PULSED AND ARC OSCILLATION TECHNIQUES OF GTA WELDED AZ31B MAGNESIUM ALLOY JOINTS
The challenges of achieving significant weight reduction in the automobile industry in the context of fuel savings, recyclability and emission reduction has promoted focus on lightweight metals such as magnesium. GTA welding technology is the main welding method adopted for magnesium alloys because of its advantages of utility and economy. Both magnetic arc oscillation and current pulsing techniques resulted in significant microstructural refinement in weld fusion zone. Hence in this investigation an attempt has been made to study the arc pulsing and arc oscillation on tensile and microstructural characteristics of pulsed current gas tungsten arc welded AZ31B magnesium alloy joints. From this investigation, it is found that the joints fabricated with magnetic arc oscillation having the superior tensile properties compared to pulsed current welding. The formation of fine grains and higher hardness in fusion zone are the main reasons for the superior tensile properties of these joints