新しい素材を用いたねじの開発

（マグネシウム合金を中心としたねじ成形とその特性）

抄録

Technology of screws made steady progress in reliability of fastening and joining in response to the requirements from the industry and society. While steel screws are widely used in the current industry and their standardization was quite advanced, problems remain unsolved in a certain fastening application. They seem to be not soluble as long as using the conventional screw materials represented by steels. Therefore, we need to take a comprehensive approach to solve the problems not only by enhancing designs but also by innovating materials. Newly developed screws using three unconventional materials, magnesium alloys, metallic glasses, and extremely small-grain pure titanium, are proposed here as a solution of each problem arising recently. The manufacturing processes that play an important role in reliability of screws are presented as well as their mechanical properties in comparison with those of steel screws.