Consistent machining of electrical discharge machining power supply towards hip implant surface texturing

Abstract

Electrical Discharge Machining, EDM is one of the technologies used for surface texturing such as the embedded micro-dimples on the metallic acetabular cup. During the machining process, changes in the gap distance may lead to load changes from open to short circuit. Limiting the load current under short circuit conditions and load voltage under open circuit conditions is the requirement in this system. Power supply is one of the elements that controls the process parameters which is related to improve the machining condition as well as Material Removal Rate (MRR). A considerable number of power supply design method were proposed for various EDM application. This research proposed a Switch Mode Power Supply method implementing new design of Flyback power supply which can stabilize the voltage during open circuit condition as well as during discharge condition. Experimental studies were conducted to verify the capability of Flyback power supply by machining eight micro-dimples in lower position and twelve micro-dimples in upper position, both in circular arrangement on metallic acetabular cup. Research conducted shows that the Flyback power supply improve the consistency of MRR when compared to Linear power supply. This may help to predict the machining time, thus improving the production of microdimples in required time.