Influence of debris accumulation on material removal and surface roughness in micro ultrasonic machining of silicon

Although micro ultrasonic machining (USM) has been successfully applied in generating micro features in hard and brittle materials such as silicon, the influence of machining parameters on the machining performance is not clearly understood. Experimental results show that the machining speed decreases with an increase in the static load beyond a certain level. In this study, the debris accumulation is proposed as the main reason leading to low machining efficiency. A mathematical model is also developed to analyze this phenomenon qualitatively. Experimental results reveal that the particle size is the dominate factor influencing the surface roughness in micro USM.