GB1141409A - Heat treatment and working of titanium alloys - Google Patents

Abstract

1,141,409. Improving physical properties; working at specified temperatures. CONTINENTAL TITANIUM METALS CORP. G.m.b.H. 23 Jan., 1967 [24 Jan., 1966], No. 3390/67. Heading B3V. [Also in Division C7] Titanium alloys containing in the annealed condition up to 25% of the beta phase at room temperature are heated to above the beta transus to achieve substantially complete transformation, quenched to partially transform the beta phase to alpha or to a martensitic phase which transforms to alpha on subsequent heating, and worked at a temperature sufficiently below the beta transus to effect spheroidization of the alpha grains. The initial heating, during which working may be effected, may be to a temperature between 50‹ and 100‹ F. above the transus, while quenching should be to at least 30‹ F. below the transus, and is preferably to ambient temperature. At least 50% deformation should then be effected, at a temperature not more than 400‹ F. below the beta transus, and this may be followed by a stress relief anneal at 1350‹ F. for 2 hours in the case of alpha-beta alloys, or at 1650-1675‹ F. for 1 hour followed by 1050-1100‹ F. for 8 hours and air-cooling in the case of alpha or lean beta alloys. Particular alloys referred to are Ti/ 2À5% Sn/5% Al, Ti/5% Al/5% Sn/5% 'Zr, Ti/ 7% Al/12% Zr, Ti/6% Al/4% V, Ti/8% Al/1% Mo/1% V, Ti/5% Al/5% Sn/5% Zr/1% Mo/1% V, while hot-working temperatures were in the range 1750-1875‹ F.