A simple method for polishing of curved CVD diamond film with silicon nitride ceramics in air is proposed. The polishing experiment was carried out using silicon nitride ceramics with different components, and the surface roughness, polishing temperature, and amount of wear of silicon nitride ceramics were examined. The results showed that silicon nitride ceramics are effective as abrasives when the silicon nitride particle size is large and both hardness and porosity are low. These ceramics increased polishing temperature and decreases the amount of wear on the ceramics themselves. The optimum silicon nitride ceramics are discussed. It is expected that silicon nitride ceramics will have a marked effect on the polishing of CVD diamond films.

We developed a built-in mist collector that collects mist generated by machine tool machining, which can be installed in the sealed sheet metal cover of the machine tool, eliminating the need for installation space.To improve the working environment in factories where machine tools are installed, it is important to collect mist generated during machining using coolant and prevent it from being discharged outside the machine. We examined the principle of mist generation and its problems, and propose a solution involving installation of a built-in mist collector on the machine tool that requires no separate installation space.This paper reports the results of a study on the basic characteristics of the mist collector, taking machining performance into consideration.

Recent social conditions necessitate reduction in use of the rare earth, cerium oxide. Therefore, we attempted to reduce the amount of cerium oxide used as fixed abrasive grains to improve retention by compounding abrasive grains. We have developed a composite abrasive fiber-bonded grinding wheel with twin-nozzle PELID, which combines cerium oxide and iron oxide, and investigated its machining performance. It was shown that the grinding characteristics can be improved by varying the mixing ratio of iron oxide in the fiber without agglomeration.