MANUFACTURE OF TI-AL INTERMETALLIC COMPOUND-SERIES TI ALLOY EXCELLENT IN STRENGTH AND DUCTILITY

摘要

PURPOSE:To manufacture a Ti-Al intermetallic compound-series Ti alloy improved in strength and ductility by successively subjecting a Ti-Al intermetallic compound-series Ti alloy having a specified componental compsn. to soln. treatment and cycle heat treatment under specified conditions. CONSTITUTION:A Ti-Al intermetallic compound-series Ti alloy contg., by atom, 38 to 50% Al, furthermore contg. total 0.1 to 5% of one or two or more kinds of elements among Cr, Ru, Mo, W, Mn, Ni, Cu, Fe, V, Nb, Ta, Ag and Co and the balance Ti with inevitable impurities is subjected to soln. treatment at a prescribed temp. of 1300 to 1500 deg.C. Next, cycle heat treatment of repeatedly executing heat treatment of reducing its temp. to an alpha single phase temp. range, then executing alpha signal phase converting treatment to form its phase into an alpha one formed of the closest hexagonal system, thereafter raising its temp. to a beta single phase temp. range, then executing beta single phase converting treatment to form its phase into a beta one constituted of the body-centered cubic system. In this way, the grain size of the structure is refined to obtain a Ti-Al intermetallic compound-series Ti alloy improved in strength and ductility.