On tool wear in rotary tool micro-ultrasonic machining

Abstract

Micro-ultrasonic machining (micro-USM) is used to fabricate complex micro-features in brittle and hard materials. In micro-USM, both dimensional and form accuracy of machined component depend mainly on the shape of the tool. However, tool wear is an unavoidable phenomenon of this process, which affect the accuracy of micro-feature. The tool suffers by three types of wear (longitudinal, lateral and edge wear) in micro-USM. Accumulation of micro-chips and abrasives in the machining gap (between tool and workpiece) are the main reasons responsible for severe tool wear in micro-USM. This article reports on a new method named as rotary tool micro-USM to reduce tool wear. The rotary tool micro-USM involves abrasive slurry with providing simultaneous rotation and vibration to the tool. Rotation of the tool helped abrasives to replenish from the machining gap easily. Micro-channels were fabricated and characterized by using stereo microscope. From the results, it was found that rotary tool micro-USM resulted in very less tool wear and as a result of that micro-channels of better dimensional and form accuracy were developed.