TITANIUM ALLOY BILLET, METHOD FOR MANUFACTURING TITANIUM ALLOY BILLET, FORGED TITANIUM ALLOY MATERIAL, METHOD FOR MANUFACTURING FORGED TITANIUM ALLOY MATERIAL, AND METHOD FOR MANUFACTURING AIRCRAFT COMPONENT

摘要

PROBLEM TO BE SOLVED: To provide a titanium alloy billet excellent in terms of ultrasonic inspectability and mechanical characteristics, a method for manufacturing a titanium alloy billet, a forged titanium alloy material, a method for manufacturing a forged titanium alloy material, and a method for manufacturing an aircraft component.SOLUTION: A titanium alloy billet 10 forged within an α+&bgr; region consisting of α titanium having an HCP structure and &bgr; titanium having a BCC structure has the following characteristics: the average particle diameter of granular α titanium is 6 μm or above and 15 μm or below; the maximal size of a colony provided as an aggregate of the granular α titanium is 120 μm or below; and an accumulation of c axes of an α titanium phase is present over a range of ±40° or less from the longitudinal direction of the titanium alloy billet in a state where the integration degree thereof at the center of a cross section D perpendicular to the longitudinal direction is 1.5 or above.