Experimental study of micro-arc machining of ZrO ₂ ceramics based on assistive electrode method

To address the problem that non-conductive materials such as ZrO 2 ceramics are difficult to process using discharge technology. In this paper, a micro-arc discharge machining method with the aid of an assistive electrode is proposed. The feasibility of micro-arc machining of ZrO 2 ceramics was experimentally investigated, and the removal mechanism of micro-arc machining of ZrO 2 ceramics was analyzed, as well as the influence laws of the voltage and pulse on time ( T on ) on material removal rate (MRR), circularity error (CE) and electrode wear rate (EWR). The results show that the micro-arc machining of ZrO 2 ceramics has been successfully realized with the help of a titanium powder sandwich-type conductive layer, the minimum effective voltage for micro-arc machining of ZrO 2 ceramics is 5 V, and the dominating material removal mechanisms are thermal cracking and thermal spalling. When the voltage selection 15 V, T on selection 2000 μs, the MRR reaches the highest at 0.33 mm 3 /min, and the EWR and the CE are relatively low at 0.24 mm 3 /min and 1.98%. The obtained outcome can provide a theoretical basis for subsequent micro-arc machining of non-conductive ceramics.