PURPOSE: To produce a titanium alloy having an accurate dimension same to a metallic die and a fine surface by restraining reaction of a titanium alloy material and the metallic die to prevent burning between them in a forging process.
CONSTITUTION: Immediately after setting the titanium alloy material in the metallic die heated to 700-1000°C under the atmospheric pressure, forging is started at a speed equal to or lower than 20mm/minute and the forming is carried out. From the time at which the material is set in the die, a thin oxidized film is formed on the surface of the material. The formed products having an accurate dimension same to the die and a fine surface is obtained without using a lubricant by restraining the reaction of the material and the die by the thin oxidized film and preventing the burning.
KUBOKI ISAO
WAKABAYASHI YUTAKA
