Wear Mechanisms of Ceramic Vibratory Finishing Media

Abstract

Vibratory finishing is a common manufacturing process that can be used for many applications such as deburring, edge rounding and polishing of surfaces. In this process, material removal is caused by an irregular relative motion between workpieces and a bulk of loose abrasive media. A wide variety of media is used, i.e. different shapes, sizes and compositions. The composition of media differs in terms of the binder which can either be resin or ceramic, and the abrasive grains typically being aluminium oxide or silica. Ceramic media, which is the focus of this publication, is the most common media because of its low cost and high material removal rates. At present, there is no sound understanding of the wear of ceramic media. During a vibratory finishing process, each particle of media is in contact more frequently with other particles than with the workpieces. This induces media wear resulting in decreasing media size and under certain conditions, lowering cutting rates. Up to now, wear mechanisms of vibratory finishing media are scarcely understood. In this publication, it is shown that wear mechanisms of conventional grinding tools can be observed on vibratory finishing media too. Media condition is observed at several different times-of-use starting from zero (fresh media) up to 300 h. For the first time, single media particles are tracked over a long time-of-use. This allows for observing certain abrasive grains. Based on microscopy and topographic analyses, wear can be identified on grain level. This reveals the prevailing wear mechanisms of the ceramic media.