Research on efficient oxygen-assisted atomized discharge ablation drilling of YG8 tungsten carbide

The YG8 tungsten carbide material is extensively utilized for its superior strength, hardness, and wear resistance, thereby placing greater demands on its drilling techniques. To address this, this study employs oxygen, which has a combustion-supporting effect, as the gaseous medium in near-dry electrical discharge drilling (N-EDD). By utilizing the exothermic chemical reaction between oxygen and steel under high temperature and pressure to release substantial chemical energy, efficient material removal is achieved, enabling high-efficiency drilling of YG8. Experimental results show that oxygen-assisted atomized discharge ablation drilling (OA-DAD), compared to air-assisted near-dry electrical discharge drilling (AN-EDD), improves the material removal rate (MRR) by 144.8%, increases the machining depth (De) of fixed-depth holes by 3.12%, reduces electrode wear rate (EWR) by 50.14%, and results in less residual core material. MRR shows an upward trend as rotational speed increases. To examine the main and interaction effects, along with their significance on various optimization criteria, an L27 (35) orthogonal array was employed. Furthermore, the optimal parameter combinations for each single-objective optimization were determined. Through parameter optimization experiments, an optimal MRR of 165.63 mg/min, a minimum overcut (OC) of 0.31 mm, and a machining hole with a depth deviation of −0.01 mm were achieved, verifying the accuracy of the optimal process parameter combinations for each indicator. Grey relational analysis was applied for multi-objective optimization of orthogonal experimental data, producing a hole exhibiting a MRR of 93.1 mg/min, OC of 0.67 mm, and De of 4.95 mm, thereby greatly enhancing both material removal efficiency and machining accuracy.