ABSTRACT The influence of shielding gas (argon, helium) on the cathode spot (CS) behaviours in aluminium AC TIG welding was investigated by the high-speed (500,000 fps) observation. Moreover, the temperature of the weld pool surface was measured by the two-wavelength pyrometer method to discuss its relationship with the CS. Consequently, the average current per CS in the helium case was 16.7 A, higher than 7.6 A in the argon case. The larger current per spot is considered to cause the higher velocity of the CS on liquid surface in the helium case (168 ± 41 m s−1) than that in the argon case. The average number of the CS was almost zero within around a radius of 2.0 mm in helium, which had the temperature above 1300 K.

中文翻译：

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保护气体对铝钨极惰性气体保护焊阴极光斑行为的影响

摘要 通过高速 (500,000 fps) 观察研究了保护气体（氩气、氦气）对铝 AC TIG 焊接中阴极点 (CS) 行为的影响。此外，采用双波长高温计法测量熔池表面温度，讨论其与CS的关系。因此，氦气情况下每个 CS 的平均电流为 16.7 A，高于氩气情况下的 7.6 A。每个点的较大电流被认为导致在氦气情况下 (168 ± 41 m s−1) 比氩气情况下液面的 CS 速度更高。在温度高于 1300 K 的氦气中，半径 2.0 mm 附近的 CS 平均数几乎为零。