Journal of Welding and Joining

The Korean Welding and Joining Society (대한용접접합학회)
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Weldability Increase of Aluminum by Variable Polarity Arc

가변 극성 아크의 알루미늄 용접성 향상에 관한 연구

  • Cho, Jungho (School of Mechanical Engineering, Chungbuk National University)
  • Received : 2014.01.17
  • Accepted : 2014.02.19
  • Published : 2014.02.28
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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

References

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Cited by

  1. Numerical analysis of variable polarity arc weld pool vol.30, pp.9, 2016, https://doi.org/10.1007/s12206-016-0845-7