Effect of ultrasonic vibration on the machining performance and mechanism of hybrid ultrasonic vibration/plasma oxidation assisted grinding

Abstract

The effect of ultrasonic vibration on the machining performance in the hybrid ultrasonic vibration/plasma oxidation assisted grinding (UPOAG) of a titanium alloy (Ti-6Al-4V) is experimentally investigated. This novel machining technology, i.e., UPOAG, provides benefits to the grinding of Ti-6Al-4V by reducing the grinding forces and chip adhesion on the grinding wheel, and improving the surface quality and material removal ratio. The effects of such improvements can be enhanced by increasing the ultrasonic vibration amplitude. It is found that the intensity of plasma discharge increased with an increase in the vibration amplitude, which can reduce the microhardness of the plasma oxidized layer on the Ti-6Al-4V specimens. X-ray photoelectron spectroscopy revealed that the plasma oxidized layer is mainly composed of TiO2 and Al2O3. Based on these, the mechanisms behind which the applied ultrasonic vibration improves the machining performance were discussed. The research findings may provide an in-depth understanding on the mechanisms of the UPOAG machining processes, as well as theoretical guidance for the application of UPOAG in the high-efficiency and high-precision machining of titanium alloy parts.