This paper discusses the groove generation mechanism and grinding path control of the grain cutting edge on small bore internal surfaces using ultrasonic assisted grinding for texturing. Single diamond grain tools were manufactured and single grain ultrasonic assisted internal grinding experiments were performed. An ultrasonic assisted internal grinding method achieved a change in grinding groove form and reduced grinding forces. The effects of grain cutting edge form were discussed between a sharp grain cutting edge and a flat grain cutting edge. Fundamental results in ultrasonic assisted internal grinding were confirmed.

With the demand for hard disk drives (HDDs) increasing as long-term storage devices, cost reduction and mass production of glass substrates used for HDDs are required. Currently, fixed abrasive polishing, which uses diamond sheet and coolant, is applied for primary polishing in the production of glass substrates. However, the effects of various coolants on the polishing characteristics have not been clarified. On the other hand, although the effects of the main components of the coolant are mostly unknown, it can be considered that some physical phenomena depending on the removal rate are occurred. This study was performed to determine guidelines required for highly efficient polishing of glass substrates with diamond sheet from the viewpoint of physical properties of coolant and its behavior during polishing. This study focused on the coefficient of friction during polishing, the kinematic viscosity of the coolant, and the physical phenomena of iris pattern as factors affecting the removal rate. Furthermore, multiple regression analysis was performed to identify the performance of coolant and the factors affecting the removal rate. The results confirmed that the kinematic viscosity of the coolant, the friction coefficient, and the iris pattern play important roles in the glass polishing process using diamond sheet.

In contour grinding of a curved surface, especially grinding of the inner surface of a corner, the contact arc length becomes large and the grinding force increases, which leads to deflection of the grinding wheel shaft and an increase in grinding heat, resulting in deterioration of shape accuracy and grinding burn. Here, grinding fluid supplied from the inner side of the grinding wheel was applied to inner surface grinding with a small-diameter grinding wheel, and the effects on temperature and grinding force were investigated. In addition, the heat partition ratio of the grinding energy to the workpiece was investigated analytically. The results showed that supplying the grinding fluid from the inner side of the grinding wheel prevented clogging of the grinding wheel and reduced the grinding energy, with cooling capacity equivalent to that with the external supply of grinding fluid.