| 摘要: |
| 应用天体物理等离子鞘层理论的知识,分析金属板测量尾焰时产生电压和探针测量等离子云时产生电压的原因。当把探针放置在等离子云中,由于等离子体的特殊性,将在探针上产生了负电位,与工件电位差就是鞘层电压,并给出鞘层电压的计算公式,通过分析发现,鞘层电压大小仅仅与检测处等离子体温度和成分有关。提出了一种用无电源探针检测等离子云的新方法,通过检测等离子云中探针上产生的鞘层电压是否为零来判断小孔是否形成。试验验证了鞘层理论在等离子弧焊接中应用的正确性,同时给出了探针放置的最佳位置。 |
| 关键词: 鞘层 小孔 等离子弧焊 尾焰电压 鞘层电压 |
| DOI： |
| 分类号: |
| 基金项目:国家自然科学基金资助项目(50275106) |
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| Detection of plasma sheath voltage in plasma arc welding |
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SHAN Ping, YI Xiao lin, HU Sheng sun, LUO Zhen
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School of Materials Science and Engineering, Tianjin University, Tianjin 300072, China
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| Abstract: |
| On the basis of theory of plasma sheath,the paper expounds the mechanism that plate or probe has negative potential when detecting plasma efflux or plasma cloud.If the probe is located in the plasma,there is a negative electromotive force in the probe.It offers the formula to compute plasma cloud voltage.The value has only something to do with temperature and plasma component.A device of detecting plasma cloud without power supply is designed.The keyhole is formed if the sheath voltage is zero.The experiment proves the theory of the sheath.At the same time,the paper gives the right location of probe to detect the plasma cloud. |
| Key words: plasma sheath keyhole plasma arc welding sheath voltage |
