ABSTRACT
Micromachining of brittle and hard materials can be performed for microfabrication using the principle of ultrasonic micro-machining (USM) as well as the ultrasonic-assisted advanced electro-micromachining process. The present chapter includes the ultrasonic micro-machining processes for generating various micro-features such as micro-holes, micro-slots, micro-walls, etc. In ultrasonic micro-machining, the ultrasonic vibration of micro-tool is transmitted to the abrasive particles of micron size present in the slurry, and the repetitive impact of abrasive particles with ultrasonic frequency utilized for material removal due to mechanical failure such as brittle fracture of brittle and workpiece materials. In assisted hybrid micromachining ultrasonic vibration of a tool or workpiece plays an important role in increasing the MR and accuracy. In assisted electro-machining, ultrasonic vibration of micro-tool assists the material during electromachining, such as micro-electric discharge machining (EDM), micro-electrochemical machining (ECM), and micro-electrochemical discharge machining (ECDM). In ultrasonic-assisted micro-EDM, material removal is 22enhanced due to better flushing and cavitation effect. For micro-drilling and micro-fabrication of slots and grooves, ultrasonic-assisted micro-EDM is applied. In ultrasonic-assisted ECM, higher MR is obtained due to the efficient removal of precipitates of chemical compounds. The present chapter also includes a discussion on ultrasonic-assisted micro-EDM, ultrasonic-assisted micro-ECM, and ultrasonic-assisted micro-ECDM utilized for micro-fabrication.
