Abstract:

Electrical discharge milling experiments on high resistivity semiconductor silicon were conducted,and processing conditions under three kinds of conduction modes as fixed,rotating,and follow-up were compared.Results show:in fixed conduction mode,as the non-conductive passive film is gradually formed on the electrical conduction spot,contact resistance increases,total resistance in the circuit continues to rise,
discharge peak current decreases,and as a result, the machining process is unable to continue;in rotating conduction mode,as the distance between the inlet-electrode and machining area getting long,bulk resistance in the discharge circuit increases,and consequently discharge peak current gradually decreases;in follow-up moving conduction mode,the inlet-electrode in discharge circuit will continuously clear off the generated passive films and maintain the distance between electrodes,
therefore,contact resistance and bulk resistance remain steady,leading to the good stability of condition in discharge machining.

Key words: electrical discharge machining(EDM), high resistivity silicon, conduction mode, resistance, follow-up conduction

摘要：

进行了高阻半导体硅的放电铣削加工实验,通过检测脉冲放电电压和电流波形,对固定、旋转、随动三种进电方式下的加工情况进行了对比。结果表明：固定进电方式下,由于进电点会逐步生成不导电的钝化膜,接触电阻不断增大,回路中的总电阻不断增大,放电峰值电流逐步减小,最终导致无法加工;旋转进电方式下,由于进电电极与加工区域距离增大,导致放电回路中的体电阻不断增大,放电峰值电流也会逐步减小;随动进电方式下,放电回路中进电电极会不断刮除产生的钝化膜且极间距离维持不变,因此接触电阻和体电阻能保持始终稳定,放电加工稳定性较好。


关键词: 电火花, 高阻硅, 进电方式, 电阻, 随动进电