There has been a great deal of recent interest in allergic reactions to the metals used for dental applications, and there is concern about the biomedical use of metallic materials. Pure titanium has excellent biocompatibility, and shows reduced possibility of metal allergy. However, the machining of pure titanium is very difficult due to its low thermal conductivity and high chemical reactivity. Therefore, pure titanium is not widely used in dental materials. Recently, we developed Ti-Ag alloys and investigated their properties. The mechanical properties of the Ti-Ag alloys were superior to those of pure titanium. These are candidates for unique dental metallic materials. In this study, a polyurea resin-bonded mounted silicon carbide wheel was developed for polishing of Ti-Ag alloys. Using this mounted wheel, polishing of the Ti-Ag alloys was achieved in a shorter time compared with three commercial mounted wheels designed for use by dentists and dental technicians. In addition, the roughness of the polished surface became smaller and the surface integrity was high in quality.

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The magnetic field-assisted machining method is effective for finishing minute corrugated surfaces and free-form surfaces. In this study, as basic research regarding magnetic field-assisted machining using electrolyzed reducing water-based slurry, we investigated the removal capability and machined surface properties. The results indicated that the influence of grain concentrations on removal capability is smaller than that of the conventional method using metal working liquid-based slurry. A machined surface with uniform polishing streak is obtained in comparison with the conventional method. Furthermore, compressive residual stress of the machined surface was greater than that of the conventional method.

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This study describes a 3-dimensional consideration of path interval in filleted end milling. Path interval is a machining condition able to adjust the balance between manufacturing efficiency and machined surface quality. In multi-axis filleted end milling, considering path interval it is practically essential to view the machining situation based on 3-dimensional geometry. However, only a few studies have been reported on the subject since the geometrical treatment is complicated. This study indicated that a point corresponding to a predetermined scallop height could be on a torus surface after a torus was modeled for the cutting edges of filleted end mill. A computational algorithm was proposed and verified to estimate the path interval in filleted end milling with tool inclination angle along the feed direction.

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