对单晶硅电火花加工过程中的电流爬坡式上升现象进行了研究,结果表明,爬坡式电流主要是由加工过程中接触电阻的变化引起的,而接触电阻主要由高温区的接触面积决定。对爬坡式电流曲线的性质进行了研究,分析了温度、热导率和相变能量对接触电阻和放电电流变化的影响。最后,研究了电参数对加工效率的影响,结果表明采用大脉宽、高电压和小占空比能够大大提高加工效率。
The phenomenon of climbing type current in semiconductor EDM was studied. Results show that the main influence factor that leads to the climbing type current is the changes of the contact resistance. The value of contact resistance is decided by the contact area of the high-temperature region. Properties of climbing type current curve were researched and the influences of temperature, thermal conductivity and phase change energy on contact resistance and current were discussed. At last, the influences of electric parameters on the machining process were researched. It is found that big pulse width,high voltage and small duty ratio can increase the processing efficiency greatly.