Silicon carbide (SiC) is a good candidate material for next-generation semiconductors for use as power devices. However, new precision and efficient processing technologies for SiC substrates over 4 inches in diameter are required for wide application of SiC power devices. We developed a specular surface processing technology for super-high-hardness materials, such as a diamond and SiC. In this research, the validity of UV irradiation and controlling polishing atmosphere were investigated. In addition, we investigated the final UV- polishing using a tube-type crystal tool against 4-inch SiC substrate. The results of X-ray photoelectron spectroscopy (XPS) indicated that UV irradiation can generate an oxide film on the SiC surface. The polishing rate in the polishing atmosphere with 100% O₂ was increased by 1.73-fold compared to that in air. The smooth polished surface with 0.2 nmRa—0.5 nmRa and 1 μm flatness was achieved in the UV-polished whole substrate.

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The UBMS (UnBalanced Magnetron Sputtering) method is applied to coated end mills, and various types of such tools are used in high-speed milling of SUS304. This coating film was designed to improve lubrication ability rather than heat resistance. In this paper, the influence of carbon addition method (graphite sputtering, CH₄ gas, and C₂H₂ gas) on the mechanical properties and structure of the coating film was clarified. TiCN film deposited by the UBMS method using CH₄ gas has a smooth surface and low coefficient of friction, and this structure acts as a lubricant as well as other films. Low cutting force and long tool life are obtained with CH₄-type TiCN-coated end mills compared to standard commercially available coated end mills in high-speed side milling without coolant.

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In this study, to establish a finishing technique for multiple kinds and small quantities of products by incorporating the magnetic polishing method and NC machine tools, the authors have developed a slurry discharge type magnetic polishing tool for machining centers. This magnetic polishing tool enables the discharge of chips while continuously supplying new abrasive grains to a particle brush formed in the tool nose. Therefore, magnetic polishing can be performed stably without loading. The magnet shape and arrangement of the slurry discharge type magnetic polishing tool and influence of slurry discharge on the polishing performance were studied experimentally. Furthermore, the slurry discharge type magnetic polishing tool has been applied to long-time surface polishing, and rounding edge processing, and its usefulness has been confirmed.

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The surface of a grinding wheel dressed by a prismatic diamond rotary dresser was generated and visualized by computer-aided simulation on the assumption that the grinding wheel is a homogeneous solid body and the loci of the prismatic diamonds are copied on the grinding wheel surface as they are. The effects of dressing conditions on the roughness of the dressed surface were investigated and the following results were obtained. The dressing conditions that realize dressing of the entire surface of the grinding wheel, i.e., the feed speed of the rotary dresser in single-pass dressing and the number of dressing passes in multipass dressing, can be estimated by examining the maximum height roughness of the dressed surface. The rotary dresser changes the position of contact with the grinding wheel at each dressing pass in multipass dressing. This change results in unstable dressing performance in the case of down-cut dressing.

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