Process characteristics and machining parameter optimization of high-efficiency drilling of SiCp/Al using atomized discharge ablation drilling method

Conventional drilling of aluminum matrix silicon carbide composites faces severe tool wear and high costs. This study introduces an atomized discharge ablation drilling (OA-DAD) method using an oxygen-water mixture as the atomizing medium. The exothermic reaction between oxygen and aluminum enhances performance. Experimental results show OA-DAD achieves material removal rates (MRR) 109.38% higher than conventional electrical discharge drilling (EDD) and 59.25% higher than near-dry EDD; actual drilling depth (AD) increases by 129.29% and 85.31%, respectively, with reduced hole wall taper. The work begins with single-factor experiments, followed by an L25 (55) orthogonal design and analysis of variance to optimize a single objective. Multi-objective optimization combines a particle swarm optimized backpropagation neural network with the non-dominated sorting genetic algorithm II. The optimized parameter sets yield holes with MRR 76.56 mg/min, electrode wear rate 152.47 mg/min, overcut 0.45 mm, AD 3.85 mm, and processing time 1.27 min.