Effect of ultrasonic vibration on unmixed zone formation

Ultrasonic vibration was applied to molten super-austenitic stainless weld metal during the shielded metal arc–welding process. It was observed that the unmixed zone in the weld metal was completely eliminated by high-intensity ultrasonic vibrations. This is mainly due to a complete mixing of the molten filler metal and base metal, at the freezing front, caused by acoustically induced cavitation and streaming.