Turn milling is a high-efficiency machining method. However, it is used only for rough machining because of the problem of creating nonuniform-shaped cutting marks on the machined surface. On the other hand, there is a demand for higher efficiency in finishing operations, and there has been a great deal of research to apply turn milling to the finishing process. For this purpose, it is important to improve not only the machining accuracy but also the esthetics of the machined surface. In this study, the applicability of turn milling to finishing was investigated by analyzing the influence of cutting marks created by the machining process on esthetics of the finished workpiece. Analysis of the luminance of the surface and sharpness of reflected images showed that the shape of the cutting marks affected the esthetics of the finished workpiece. The results indicated that turn milling can be used for the finishing process by controlling the shape of the cutting marks.

A fixed abrasive polishing method using a diamond sheet with a fine-tuned coolant is applied in the production of industrial glass substrates. While it is known empirically that the initial surface texture of glass substrate and the coolant affect the polishing characteristics, such as the removal rate and surface roughness, there have been insufficient systematic evaluations of the process. Focusing on these two parameters, experimental verification was performed using a double-sided polisher. The initial surface texture of the substrate was evaluated based on the transmission of white light, and the coolant characteristics were estimated by the luminance of the liquid film due to the appearance of bubbles formed on the lower platen during polishing with the upper platen removed. The results showed that the initial surface texture of the substrate has a marked effect on the removal rate, and that the removal rate was reduced the closer the initial surface texture was to a mirror surface. Furthermore, obtaining a high removal rate became more difficult when the liquid film formed on the lower platen approached white. This white color was considered to be generated due to the bubbles formed during polishing and to be related to sludge discharge performance from the platen.

This study examined the changes in BaSO₄ abrasive area ratio on stone surface and investigated superfinishing performance of single-crystal silicon. The results indicated that when BaSO₄ abrasive ratio on the working area of stone is maintained and/or BaSO₄ abrasives on stone surface are gradually crushed during superfinishing, mechanochemical stone produces better surface roughness with high crystallinity. On the other hand, when BaSO₄ abrasive ratio is greatly decreased, the stone amorphizes the surface of silicon and produces a rough surface with low crystallinity due to the action of mechanical removal.