Study on analysis of kerf width variation in WEDM of insulating zirconia

ABSTRACT

The shaping of the electrically insulating ceramic component in post sintered state has always been a difficulty in developing ceramic applications. Wire electrical discharge machining is an ascertained option to produce near net shape products in conductive materials. When it comes to insulating ceramics, sustaining the threshold electrical conductivity comes into the picture. This paper explores the feasibility of wire electrical discharge machining of Y₂O₃ stabilized ZrO₂ with graphite powder additive mixed distilled water to replace the kerosene. In this research, the assisting electrode method has been employed to provide electrical conductivity to the work material to have initial electrical contact. Sparking initiates at assisting electrode coating and further conservation of electrical contact leads to successful engraving. Along with graphite concentration, the servo reference voltage is varied to study the kerf width variation deciding the accuracy of the component. The optimum graphite concentration was found to be in the range of 3 to 5 g/ltr. For this range, the ceramic erosion experienced to be most stable through optimum kerf width. Continuous increase in the kerf was observed with increasing gap voltage for individual graphite concentration.

KEYWORDS:

• Electrically insulating ceramic
• assisting electrode
• conductive layer
• wire EDM
• dielectric Fluid

Acknowledgments

This work has been financially supported by the TEQIP-II project scheme run by Govt of India for the purchase of the Wire EDM facility on which the experiments were performed.

Additional information

Funding

This work was supported by the Ministry of Human Resource Development [TEQIP II].