Fundamental Machining Characteristics of Ultrasonic-Assisted Electrochemical Grinding of Ti–6Al–4V

The Ti–6Al–4V is a widely used alloy in the aerospace industry. In order to improve the grindability of Ti–6Al–4V, a hybrid material removal process is proposed in this study. This process is a combination of ultrasonic assisted grinding (UAG) and electrochemical grinding (ECG), hereafter called ultrasonic assisted electrochemical grinding (UAECG). For confirming the feasibility of the proposed technique, an experimental setup was constructed and the fundamental machining characteristics of UAECG in the grinding of Ti–6Al–4V were experimentally investigated. The results obtained from the investigation can be summarized as follows: (1) the normal and tangential forces in UAECG were decreased approximately 57% and 56%, respectively, comparing with conventional grinding (CG). (2) The work-surface roughness Ra both in ECG and UAECG was negative correlation to the electrolytic voltage, U_I, and the surface damage; (3) the wheel radius wear in UAECG was considerably smaller than that in ECG when U_I < 10 V. The chip adhesion and the grain fracture mainly affected the working lives of the wheels in ECG and UAECG, whereas the wheel wear in CG was predominantly attributed to the grain drop out; (4) a titanium dioxide (TiO₂) layer, which had a 78 nm thickness was achieved on the work surface in the condition of U_I = 20 V, leading that the Vickers microhardness of work surface in ultrasonic assisted electrochemical was lower than that in CG by 15%.