Iida Kenta, Komen Hisaya, Shigeta Masaya, Tanaka Manabu
Joining and Welding Research Institute, Osaka University, Osaka, Japan.
Department of Mechanical Systems Engineering, Tohoku University, Sendai, Japan.
Sci Rep. 2023 Jul 27;13(1):12210. doi: 10.1038/s41598-023-39274-4.
A unique mechanism of splashing from a tungsten-based anode was identified during arc discharge. Splashing occurred by breakoff of a liquid metal column, which elongates after a local concavity formed on the molten anode surface. Blue-violet luminescence, emitted by cerium ions originating from additives in the tungsten-based anode, was captured before the concavity formation. The surface temperature exceeded the boiling point of the additives at the time of splashing. The measured droplet speeds suggested that an electromagnetic force contributes the high-speed ejections. Energy dispersive spectrometry mapping also exhibited a remnant of the additives on the longitudinal cross-section of the anode after arc discharge. Based on these experimental facts, the mechanism of anode splashing in arc discharge was deduced as follows: bubble formation of additives at temperatures above their boiling point, bubble bursting at the surface, micro-plasma jet generation, liquid-column elongation and breakoff under an electromagnetic force, and consequent high-speed droplet ejection.
在电弧放电过程中，发现了一种基于钨基阳极的独特飞溅机制。飞溅是由液态金属柱的断裂引起的，液态金属柱在熔融阳极表面形成局部凹陷后会伸长。在凹陷形成之前，捕捉到了由钨基阳极中的添加剂产生的铈离子发出的蓝紫色发光。飞溅时表面温度超过了添加剂的沸点。测量到的液滴速度表明，电磁力促成了高速喷射。能量色散光谱映射还显示，电弧放电后阳极纵向横截面上有添加剂残留。基于这些实验事实，电弧放电中阳极飞溅的机制推断如下：添加剂在高于其沸点的温度下形成气泡，气泡在表面破裂，产生微等离子体射流，在电磁力作用下液柱伸长并断裂，从而导致高速液滴喷射。
