偏压在大尺寸活性屏等离子渗氮中的作用机理

Mechanism of Bias in Large-diameter Active Screen Plasma Nitriding

通过采用大尺寸活性屏进行等离子渗氮处理,研究和分析了偏压及其"阈值"对大尺寸活性屏渗氮的影响。实验结果表明:采用大尺寸活性屏渗氮时,加在工件上的偏压是一个决定性的因素,只有当负偏压大于"阈值"时,无论距活性屏多远的试样都能取得较好的渗氮效果。通过理论分析认为这个偏压阈值恰好是能够引起工件表面产生自溅射所需要的最低电压。研究认为采用大尺寸活性屏渗氮时,距离活性屏较远的工件是靠施加在其上的偏压引起工件表面产生自溅射生成大量的纳米粒子作为渗氮的载体实现渗氮的。

The samples were treated by means of the active screen plasma nitriding tech- nology （ASPN） with a large-diameter active screen. The experimental results showed that the bias threshold was a definitive factor for the active screen plasma nitriding with a large-diameter active screen. Unless the bias is bigger than the threshold, the samples located in anywhere of the active screen can gain a good nitriding effect. And it was proved that the bias threshold is iust the minimum voltage,which can make the sample sputtered itself and produce many particles in nanometer scale. These particles are the carrier of the active nitrogen in ASPN with a large-diameter active screen.