Research on oil film-assisted wire electrochemical discharge machining

Abstract

Wire electrochemical discharge machining (WECDM) has the potential for cutting insulating materials. In order to achieve electrochemical discharges, WECDM is usually conducted on horizontal wire setup. It makes the design of machine tool difficult, especially in machining parts which require multi-axis control. The control of electrolyte level that has a significant influence on machining stability is also a complicated problem. In addition, the electrolyte cannot be sprayed to the machining zone with a relative high velocity to ensure a good electrolyte circulation, else the vulnerable hydrogen gas film that is used to electrically insulate the tool wire from the electrolyte can be destroyed. This paper proposes an oil film-assisted WECDM method. The oil film is online covered on the tool wire, and so the electrolysis only occurs at the positions where the oil film is absent. As a result, a stable insulating film, which consists of oil and hydrogen gas, is formed on the tool wire. Experimental results showed that electrochemical discharges were obtained during machining a 10.0-mm thick quartz glass on a vertical wire setup with spraying electrolyte condition. Finally, the effects of process parameters (applied voltage, electrolyte spraying velocity, wire speed, and workpiece feed rate) on machining performance were analyzed based on cutting experiments.