Characteristics of Arc and Metal Transfer in Pulsed Ultrasonic-Assisted GMAW

Abstract

Pulsed ultrasonic-assisted gas metal arc welding (PU-GMAW) is a newly developed welding method. Pulsed frequency is one of the most important parameters in the PU-GMAW process. In this paper, the influence of pulsed frequency on the GMAW of aluminum alloy was studied. The results showed that the conventional GMAW process was improved significantly by adding different pulsed frequencies. The pulsed arc length, which was the change of arc length with the change of pulsed frequency, was obtained when the pulsed frequency ranged from 1 to 10 Hz. The stable compression arc length was obtained when the pulsed frequency exceeded 20 Hz. The metal transfer frequency in PU-GMAW in-creased compared to conventional GMAW. The increase of burning arc space pressure in PU-GMAW was mainly the reason for the change of the arc length. The increase in electro-magnetic force and acoustic radiation force was the fundamental reason for the increase in droplet frequency.