Research on Micro-hole Electrolytic Machining Process with Sidewall Insulated Electrode

Abstract

Ultrasonic vibration technology had been used in the micro holes electrochemical machining (ECM) to exclude processed products within the gap, but the impact of ultrasonic cavitation influenced the insulating layers on the electrode surface and accelerated its destruction. In order to improve the life of the sidewall insulated electrode, the double insulating layer consisting of ceramic insulating film and electrophoretic paint film was formed on the surface of the fine titanium electrode by using the micro-arc oxidation and cathodic electrophoresis. The effects of ultrasonic vibration power, electrolyte concentration and machining voltage on the micro hole machining accuracy with the sidewall-insulated electrode was analyzed. The experimental results showed that the double insulation layers displayed a strong durability in ultrasonic vibration assisted micro holes electrochemical machining. When the ultrasonic vibration power exceeded a certain value, the processing was able to stabilize. Afterwards, the machining accuracy changed little with the increase the power. It is necessary to reduce the electrolyte concentration and the machining voltage, thereby reducing the stray corrosion, for ensuring the shape accuracy of the hole in stable machining.