Precision Force Measurement and Control in Micro Ultrasonic Machining

Micro ultrasonic machining (Micro-USM) is a process with a great capability to generate micro features in hard and brittle materials. Despite some developments in micro-USM process, issues such as precision measurement and control of the machining force, which is crucial for stable machining conditions, need further investigations. In this paper, the precision measurement and control of the machining force is studied using a newly-developed force measurement configuration. The results of the force measurement for different levels of static force, abrasive particle size and amplitude of vibration demonstrated that the variation of measured machining force increases at higher static forces. Furthermore, a better control over the static load was acquired when feeding the abrasive slurry with particle size of 0.37 μm as compared to 1 μm and 3 μm particles leading to more stable machining conditions in micro-USM process. Finally, applying lower levels of vibration amplitude to the workpiece resulted in more stable machining conditions and lower static load errors.