Cutting temperature and resulting influence on machining performance in rotary ultrasonic elliptical machining of thick CFRP

As a novel non-conventional machining process, rotary ultrasonic elliptical machining (RUEM) has been successfully used for drilling thick carbon fiber-reinforced plastics (CFRPs) recently. In order to reduce the thermal damage, the measurement of cutting temperature is important when RUEM of CFRP. In this research, the cutting temperatures in both RUEM and grinding drilling (GD) were measured by an infrared camera under dry condition. Temperature trends as functions of feed rate and cutting speed were obtained and the results showed that compared to GD, RUEM can effectively reduce the maximum temperature by 18.8% and 13.1% at the feed rate of 75 and 150 μm/rev respectively. Both mechanisms of temperature reduction and chip adhesion prevention in RUEM were analyzed. In addition, SEM observation of the machined surface revealed that better microstructure was obtained in RUEM compared to GD under the same cutting condition.