An Electrochemical Discharge Ablation Compound Milling Method Utilizing Electrolyte-Oxygen Aerosol Medium

Traditional electrochemical discharge machining (ECDM) is a hybrid of electrical discharge machining (EDM) and electrochemical machining (ECM). Electrical discharge erosion and electrochemical dissolution occur simultaneously in low-conductivity salt solution. It is very difficult to reduce the recast layers because of the low ratio of electrochemical dissolution. A novel combined machining approach combining electrical discharge ablation machining and electrochemical machining (EDAM-ECM) is proposed and the “electrolyte-oxygen” aerosol is used as the medium in this study. First, the electrical discharge ablation machining (EDAM) process is performed with oxygen in the aerosol medium to attain a higher material removal rate (MRR). Second, the electrochemical reaction current is increased by using a droplet of the electrolyte with higher conductivity. Third, the ratio of electrochemical dissolution is increased in an aerosol medium. The mechanism of conventional ECDM milling and EDAM-ECM milling was analyzed and comparable experiments were performed. Results show that EDAM-ECM milling has advantages of higher MRR, lower relative electrode wear ratio (REWR), and higher surface quality. Under the prescribed test conditions, the MRR increased by more than five times and the REWR is reduced by 94.1% compared with ECDM milling, and the recast layer is completely removed.