Surface roughness optimization in processing SiC monocrystal wafers by wire saw machining with ultrasonic vibration

Being very hard and highly brittle, silicon carbide (SiC) monocrystal is considered to be a difficult-to-machine material. The machining method and process parameters greatly affect the productivity and the surface quality of the finished part. This article presents an experimental investigation of processing SiC monocrystal wafers by wire saw machining with ultrasonic vibration. Experiments are conducted for various process parameters, which include wire saw velocity, part feed rate, part speed and ultrasonic vibration amplitude. An empirical model has been developed for predicting the surface roughness when wire saw machining SiC monocrystal wafers. Response surface regression and analysis of variance are used to study the effects of the process parameters. Optimum process parameters for minimizing surface roughness are determined using the desirability functional approach. The experimental results showed that the surface roughness model can predict the surface roughness with a relative error lower than 5% when wire saw machining SiC monocrystal wafers over a range of process parameters.