The Inhibitative Effect of Low Freguency Pulsed MIG Welding Process on Blowhole Generation for Al and Its Alloy

Study on Low Freguency Pulsed MIG Welding Process (Report 3)

Abstract

Vibration of molten puddle is achieved with the low frequency pulsed MIG welding process of new current waveform to switch over two preset unit pulse conditions alternately.
In this paper, beneficial effect of reducing the blowholes which often cause problems in MIG welding of Al and its alloy was investigated by using above mentioned process under 99.9%Ar-0.1%H₂ shielding gas atmosphere.
It was made clear that switching frequency of unit pulse conditions in the range of fs=10-25 Hz had beneficial effect of reducing blowholes on various wire-base metal combinations, welding speed and flat, vertical-up and horizontal positions.
Moreover, this process was effective in reducing the blowholes for Al cast alloy.