Analysis of surface generation in the ultraprecision polishing of freeform surfaces

Abstract

The use of freeform designs in engineering surfaces has become increasingly popular over the last decade. Applications of freeform shapes range from aesthetics of components to the bending of light rays through advanced optic designs. The fabrication of the components for these applications requires submicrometre form accuracy, in some cases with surface roughness at nanometric levels. Ultraprecision polishing is an emerging technology for the fabrication of high-precision and high-quality freeform surfaces. However, the factors affecting nanosurface generation in ultraprecision polishing have received relatively little attention. Moreover, the quality of the polished surface relies heavily on appropriate selection of process conditions and polishing strategies. This paper presents an analytical study of the factors affecting surface generation in ultraprecision polishing. A series of polishing experiments have been designed and undertaken, allowing the relationships between various factors and the surface quality of the workpiece to be determined. The results of the study provide a better understanding of nanosurface generation, as well as the strategy for optimizing surface quality, in the ultraprecision polishing of freeform surfaces.

State of the art of bioimplants manufacturing: part I

“…Machining bioimplants by means of grinding processes followed by polishing is a favourable solution for removing the remained damages. Figure 8 shows the surface quality with and without a finishing process of polishing [123]. It was reported that a smoother surface exhibited a better corrosion resistance, and hence prolonged the lifetime of the implant.…”

“…It was reported that a smoother surface exhibited a better corrosion resistance, and hence prolonged the lifetime of the implant. In addition, the conformity between the coupling joints would reduce the friction coefficient, which was very attractive with respect to the bearing orthopaedic implants [123,124]. Conventional polishing methods include free abrasive polishing, fixed abrasive polishing, belt polishing, etc., which have all been comprehensively investigated in the past decades.…”

“…In pursuit of a higher level of surface finish, researchers dedicated to the study of ultraprecision polishing. Cheung et al [123] investigated the Fig. 7 Schematic illustration of the new ELID grinding system for machining hemispherical inside surface [122] factors that might affect the nanosurface generation in ultraprecision polishing.…”

“…Fig. 8 Surface quality of an artificial knee implant a without and b with polishing [123] State of the art of bioimplants manufacturing: part I 33…”

Precision glass molding: Toward an optimal fabrication of optical lenses

“…Traditional methods of fabricating glass lenses are grinding, polishing and lapping [22][23][24][25], dating back to the 1500s when microscopes [26,27] and telescopes [28][29][30] were invented. However, lens polishing skills were among talented craftsmen [26,28], developed from their life-long experience.…”