Rotary Ultrasonic Surface Machining of CFRP Composites: A Comparison with Conventional Surface Grinding

Rotary ultrasonic machining (RUM), a hybrid nontraditional process technology combining ultrasonic machining and grinding, has been proven to be a promising method for hole making of CFRP. Due to its advanced capabilities, RUM has been further extendedly applied in surface machining: rotary ultrasonic surface machining (RUSM). Carbon fiber reinforced plastic (CFRP) composites have found extensive applications in areas such as aerospace, automotive, and sports due to their superior material properties. CFRP components are usually near net shaped after molding processes, however, additional surface machining is still required to generate the final dimensions and functional surfaces of the advanced CFRP components especially with three-dimensional features. However, the investigations on RUSM of CFRP are very limited and there are no reported studies on comparisons between RUSM and conventional surface grinding (CSG) of CFRP. In this paper, for the first time, a comparative study between these two processes of CFRP in the aspects of axial and infeed-directional cutting forces, torque, and surface roughness is conducted. In order to better understand the material removal differences between these two processes, the kinematic motions of the abrasive grains are also analyzed and compared.