Research on milling performance of titanium alloy in a new hybrid process combining short electric arc and electrochemical machining

In this paper, aiming at re-solidified layer problem on workpiece surface in short electric arc machining (SEAM), a new hybrid process (SEACM) combining SEAM and electrochemical machining (ECM) was proposed using a mixture of NaCl solution and air with electrolytic and dielectric properties as working medium to achieve the effect of removing surface re-solidified layer by enhancing the electrochemical interaction between the poles during short electric arc machining. By discussing the influence of gas pressure in working medium on the machining performance of SEACM, the process was divided into two kinds of SEACM machining forms: efficiency-first and quality-first. Combining the advantages of the two machining forms in material removal rate (MRR) and surface quality, a combined machining mode was proposed. The MRR, specific energy consumption (SEC), surface morphology, cross-sectional morphology, chemical composition and microhardness after combined machining mode of titanium alloys were analyzed. The experimental results show that the MRR after combined machining exceeded 450 mm(3)/min, the SEC was 233.6 kJ/cm(3), and the surface of the workpiece was basically free of defects. The surface roughness Sa was only 389 nm, and the re-solidified layer and heat-affected layer were completely removed.