Grinding-assisted electrochemical discharge machining of ZrO₂ ceramics with constant force feed control

Abstract

Grinding-assisted electrochemical discharge machining (G-ECDM) shows great potential for efficient and high-precision machining of insulating hard and brittle materials such as glass. However, research on ZrO₂ ceramics, which have higher melting points and lower thermal conductivity, is still relatively lacking. To expand the application range of G-ECDM and address the thermal defects that occur in ZrO₂ ceramics in conventional ECDM, this paper proposes a G-ECDM method based on constant spring force feedback feed. This approach aims to achieve faster removal of material affected by discharge heat through the grinding action of the abrasives, thereby avoiding excessive heat accumulation inside the material, and reducing the generation of thermally induced cracks with larger overcut. The feed force can be effectively controlled by means of a constant spring force feed, enabling better conditions for the synergistic action of grinding and discharging and preventing damage to the tool electrodes. In addition, previous research on G-ECDM has primarily focused on the grinding effect of abrasive tools, with few studies addressing the effects of the process on gas film formation and discharge. Therefore, this paper also investigates the impact of abrasive electrodes on gas film formation and discharge properties, while also examining the removal mechanism of ZrO₂ ceramics during G-ECDM. Through a series of process parameter optimizations, high-quality small hole machining of ZrO₂ ceramics was successfully achieved. This research provides an important basis for improving the theory of the G-ECDM process and expanding its application in high-temperature engineering ceramics.