TITANIUM MATERIAL LESS SUSCEPTIBLE TO DISCOLORATION AND METHOD FOR PRODUCTION THEREOF

摘要

Titanium material less susceptible to discoloration and method for thereof are provided. Titanium materials less susceptible to discoloration in the atmosphere are obtainable by controlling the fluorine and carbon contents in the oxide film on the surface thereof and the thickness of the oxide film. Such titanium materials are obtainable by dissolving the surface thereof in an aqueous fluonitric acid solution with a nitric acid concentration of not higher than 80 g/l or heat-treating at between 300 and 900 DEG C in a vacuum or in an inert gas atmosphere of argon or helium after dissolving in the aqueous fluonitric acid solution.