6 - Lapping and Polishing

Abstract

Lapping and polishing occur by the sliding frictions between particles and a surface. The lap or polisher travels across a work surface against which particles of sand or mud-type slurry are forced to the point of contact. The present processing technology, which belongs to the 4th generation, an improved version of the 3rd generation technology, has been applied to the fabrication of optical, electronic, and mechanical devices. A study on an automatic or computer aided machining system for both processing and ultra-precision polishing has been undertaken for practical use. Lapping and polishing are considered as two of the most outstanding processing methods because of their capability to secure high accuracy. The main difference between the lapping and polishing processes is obvious in glass lens manufacturing. Lapping produces a rough surface processed with coarse abrasives and a hard plate tool, while polishing produces a mirror-like surface processed with fine particle abrasives and soft pads. This chapter discusses principles of lapping and polishing for hard and brittle materials, like optical glass and crystals belonging to the group of ceramics, while also discussing the ultra-precision processing technique.