Combined milling of electrical discharge ablation machining and electrochemical machining

This paper proposes a combined milling process of electrical discharge ablation machining (EDAM) and electrochemical machining (ECM) as an alternative to the low efficiency problem of less efficient electrical discharge machining (EDM) and to reduce the recast layer of EDAM. The working medium was a mixed aerosol of NaCl solution and oxygen, which has electrolytic and dielectric characteristics. The mechanism was analyzed: the combined milling process was a mixed process of EDAM, ECM, and EDAM-ECM combined machining. The EDAM-ECM combined machining can be divided into three stages: the electrolysis stage, discharge channel formation stage, and rapid ablative removal stage of metal substrate. Experiments were performed to compare conventional EDM milling, EDAM milling, and combined milling of EDAM and ECM. Results showed that the material removal rate (MRR) of the combined milling was 11.5 times that of EDM milling, and it increased by 18.7% compared with EDAM milling. The relative tool wear ratio (RTWR) decreased by 46.6%, and the thicknesses of the recast layer on the bottom and side were reduced by 61.2% and 49.2%, respectively, compared with EDAM milling.