A study of electro-spark machining characteristics with electromagnetic spark-gap controlling mechanism

Abstract

Machining characteristics of a few workpiece and tool electrode materials during electro-discharge machining using electromagnet as spark gap controlling mechanism, have been investigated. Simplication of the servo-system has lowered the cost of the machine by a considerable amount. But machining characteristics are to some extent different from those when a conventional electro-discharge machine is used. The variations of workpiece material removal rate, tool wear rate, discharge frequency and wear ratio (ratio of workpiece material removal rate and tool wear rate), when supply voltage and capacitance are changed in an R-C circuit, have been studied using High Speed Steel and High Carbon Steel as workpiece materials and copper, brass and aluminum as tool electrodes. It has been found that with higher capacitance, brass electrodes are more efficient than copper electrodes; therefore for rough machining, brass electrodes should be used.