アルミニウム合金の交流TIG溶接に対する電流波形の影響

摘要

Aluminum alloy has been used in various industrial sectors because of such a desirable mechanical or metallurgical property as low density, high tolerance to corrosion and high recycling efficiency. On the welding of aluminum alloys, it is required to remove the oxide layer from the surface which prevents from making a proper weld joint. AC method is used in the TIG arc welding of aluminum alloys where the cathode spot breaks down the oxide layer covering the material surface during the period of the electrode positive (EP). The object of this study is to make clear the influence of AC current waveform on AC TIG welding of aluminum alloys. Especially, the influence of frequency and EP time ratio on the bead profile and cleaning width has been discussed in the present paper.As a result, it is made clear that the power consumption in arc space is an important factor governing the bead size, and the power consumption in EP alternation is strongly related to the cleaning action.