Nanogrinding

Nanogrinding is an ultraprecision machining process well suited for surface machining of advanced ceramics. The machining kinematic is based on a lapping process, where the workpieces, forced by friction effects, revolve on a rotating plate. Lapping uses loose grain; however, for nanogrinding, the abrasive grain is completely embedded in a soft metallic plate, thus becoming the grinding tool. Therefore, nanogrinding is a two-step process. The first step is to create the grinding plate. In the second step, the workpiece is machined. Nanogrinding requires a significant grinding plate roughness, which is achieved by conditioning the plate with pumice. During this process, pumice is embedded in the grinding plate and remains there throughout the process. Between pumice particles, the basic soft metallic plate material forms plateaus. Diamond grain is embedded here by a conditioning ring, with their summits aligned co-planar to the plate surface. This arrangement allows the performance of ductile machining, resulting in plastic material removal, minimal subsurface damage, and excellent surface finish. (C) 1997 Elsevier Science Inc.