Tanaka Limited

Other

Osaka Prefecture

Sdc Incorporated

Noriyoshi Tsuji

Shinichi Tanaka

Koichi Tanaka

Takumi Sone

Yukihiro Sato

Kei Demizu

Eiichi Ishii

Hideo Kakutani

A method of carburizing treatment is proposed in which if carburizing is carried out at a low temperature, carbon will not turn amorphose and deposit on the surface of a titanium metal but reliably penetrate into between metallic atoms. It is a method of surface treatment of a titanium metal comprising the steps of heating the titanium metal to a temperature of 400-690&#xb0; C. in a cleaning gas atmosphere containing hydrogen gas, subjecting the surface of the titanium metal to cleaning by applying a DC voltage of 200-1500 V, and plasma carburizing in an atmosphere comprising a carburizing gas having an atomic weight ratio of hydrogen atoms (H) to carbon atoms (C) adjusted to 1&#x2266;H/C&#x2266;9 at a pressure of 13-400 Pa and a temperature of 400-690&#xb0; C. Ionization reaction in the gas is suppressed suitably. Because there exists no excessive carbon which is not used for carburization but turns soot or glass-like carbon, in the atmosphere during carburization, carburizing reaction progresses smoothly.

Method of surface treatment of titanium metal

Threaded parts for aircraft

A method of forming a sufficiently thin, highly amorphous and homogeneous glass-like carbon film on the surface of a titanium metal with high efficiency. In this method, the surface of a titanium metal is polished by e.g. buffing with emery paper and alumina or chromium suspension as polishing agents to form a mirror surface. A dense and rigid titanium oxide film layer is formed on the mirror surface. The surface of the titanium oxide film is then subjected to plasma heating in an atmosphere containing a hydrocarbon gas under a gas pressure of 0.1-30 Torr at 400-1100.degree. C. to form a glass-like carbon film thereon.

Method of forming a coating of glass-like carbon on titanium metal

Growing community of inventors

Osaka, Japan

Noriyoshi Tsuji