Performance evaluation of ultrasonic abrasive machining by analysis of variance

Ultrasonic abrasive machining is a machining method in which an ultrasonically-vibrated tool presses the workpiece via free abrasive grains and induces hammering motion of free abrasives. This machining technique is especially applicable to hardand-brittle materials such as ceramic matrix composites and sufficient machining speed is practically achieved by performing micro-brittle fractures tens of thousands of times per second. Nevertheless, there are few studies that quantitatively evaluate the parameters of this machining method and their interactions. The problem is that this machining process is conducted manually and the machining conditions are determined by the experience of an operator. Hence, derivation of conditions to improve machining efficiency is required. In this study, the factor effects and their interactions among machining pressure, oscillator power and slurry flow, which are the typical parameters of ultrasonic abrasive machining, were evaluated by analysis of variance and the related experiments in monolithic SiC. As a result of analysis of variance and the related experiments, it was shown that the combination of machining pressure of 135 g/mm, oscillator power of 100 W and slurry flow of 2500 mL/min remarkably improves the machining efficiency in monolithic SiC. It was also clarified that there are significant interactions between the machining pressure and the oscillator power and between the machining pressure and the slurry flow, respectively.