An ultrasonic frequency pulse tungsten inert gas welding power source was developed. The power source topology and work principle were introduced. By contrast with current waves output from conventional tungsten inert gas welding power source, faster rising and falling pulse current edges were output from this power source at every ultrasonic pulse frequency. The pulse current change rate was up to 50�iA per microsecond. The power source was suited for welding not only sheet metal, but also medium and thick metal for base current, peak current, duty, pulse current frequency and other weld technology parameters expediently adjusted. By comparing with 1Cr18Ni9Ti austenitic stainless steel joints welded by conventional tungsten inert gas welding, these joints welded by the ultrasonic frequency pulse tungsten inert gas welding were shown grain refinement and narrow coarse grain zone in weld beads. The experiment results show that the ultrasonic frequency pulse tungsten inert gas welding power source is applicable to arc welding.
Qi Bojin, Xu Haiying, Huang Songtao, Zhang Wei, .Ultrasonic frequency pulse tungsten inert gas welding power source topology and welding applicability[J] JOURNAL OF BEIJING UNIVERSITY OF AERONAUTICS AND A, 2009,V35(1): 61-64