State-of-the-art review of micro ultrasonic machining

In ultrasonic machining (USM), hard and brittle material is removed by the hammering of abrasive particles excited by ultrasonic vibration delivered to the tool. USM does not significantly alter metallurgical, chemical, or physical properties of work material because of its non-thermal, non-chemical and non-electrical nature. USM has been downscaled to generate micro-scale features in brittle and hard materials such as silicon, quartz, glass and ceramics. Micro holes, slots and 3-D features have been machined. However, the knowledge base for micro USM is far from sufficient to provide instructive rules in applying micro USM to practical manufacturing. This paper presents a systematic literature review and reports the state-of-the-art investigation in micro USM based on previous experimental and theoretical results. Research issues are identified for further improvement of this special micromachining process.