Tribological effects of loose alumina abrasive assisted sapphire lapping by a fixed agglomerated diamond abrasive pad (FADAP)

Abstract

The tribological effects between a fixed abrasive pad (FAP) and a workpiece can effectively maintain the self-conditioning process of the FAP in real time. However, the FAP is easy to be glazed along with the long-term lapping processes of hard-to-process ceramic materials. This paper proposed a novel method of loose abrasive assisted fixed agglomerated diamond abrasive lapping (LA-FADAL) to achieve efficient and stable lapping processes of sapphire. LA-FADAL tests with a fixed agglomerated diamond abrasive pad (FADAP) were carried out by changing the particle size and volume fraction of loose alumina abrasives in lapping slurries. The influences of the different alumina abrasives on the processing performance of the FADAP were discussed. Material removal mechanisms in the LA-FADAL processes were proposed based on the tribological effects of loose alumina abrasive assisted sapphire lapping by the FADAP. The loose alumina abrasives with the similar size as the diamond grains embed in the surface of the fixed AD abrasive could not remove sapphire materials directly and effectively by mechanical actions, mainly played a role of dressing the FADAP to enhanced the self-sharpening ability of AD abrasives, and further improved the self-conditioning ability of FADAPs.