Ultrasonic-assisted electrochemical drill-grinding of small holes with high-quality

Electrochemical drill-grinding (ECDG) is a compound machining technology, which combines Electrochemical machining (ECM) with mechanical drill-grinding process. On this basis, a new method of machining small holes which called ultrasonic-assisted electrochemical drill-grinding (UAECDG) is proposed. First, the principle of UAECDG is analyzed through analysis of UAECDG process and electrochemical passivation behavior of materials. Second, the simulation of electrochemical drill-grinding process was studied to illustrate the effect of ball-end electrode on reducing the hole taper and improving the machining accuracy. Afterwards, several groups of experiments are conducted to analyze the influence of electrical parameters, ultrasonic amplitude and matching degree between electrolysis and mechanical grinding on the machining quality of small holes. Finally, small holes with diameter of 1.1 ± 0.01 mm, surface roughness of 0.31 μm and taper of less than 0.6 degree were machined by UAECDG, which revealed UAECDG is a promising compound machining technology to fabricate small holes with high quality and high efficiency.