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http://dx.doi.org/10.5781/JWJ.2014.32.1.108

Weldability Increase of Aluminum by Variable Polarity Arc  

Cho, Jungho (School of Mechanical Engineering, Chungbuk National University)
Publication Information
Journal of Welding and Joining / v.32, no.1, 2014 , pp. 108-111 More about this Journal
Abstract
Low arc weldability of aluminum alloy is enhanced by applying variable polarity TIG and the result is theoretically investigated to figure out the mechanism. Conventionally, it is well known fact that DCEP (reverse polarity) arc is effective on aluminum welding. The reason is due to oxide layer removal by plasma ion bombardment and therefore it is named as cleaning effect. Another fact of polarity characteristic is that DCEN shows higher heat input efficiency therefore conventional variable polarity arc used to apply DCEP portion as small as possible. However, higher DCEP portion shows bigger weldment in this research and it is explained by adopting a theory of arc concentration on oxide layer with tunneling effect which was not clearly mentioned before in several variable polarity TIG welding research. Disagreement between variable polarity TIG welding result and conventional arc polarity theory is rationally explained for the first time with help of electron emission theory.
Keywords
Variable polarity; Arc; Aluminum; Weldability; Cleaning effect; GTA; TIG; DCEP;
Citations & Related Records
Times Cited By KSCI : 2  (Citation Analysis)
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