PURPOSE: To attain a means of treatment for a Near beta titanium alloy, capable of providing high strength well-balanced with high fracture toughness value, with minimal anisotropy.
CONSTITUTION: A Near beta titanium alloy, having 0-6% Mo content, is subjected to solution heat treatment at a temp. not lower than the β-transformation point, then to aging treatment in an α+β region between (β-transformation point - 690°C) and (β-transformation point - 490°C), further to solution heat treatment again in an α+β region between (β-transformation point - 150°C) and the β-transformation point, and then to aging treatment in an α+β region between (β-transformation point - 340°C) and (β-transformation point - 220°C). By this method, a superior titanium alloy can be obtained, independently of previous history of working.
MAEDA HISASHI
OKADA MINORU
