Patent ID: 7704339
Filing Date: 2010-04-27
Classification: C22C,C22F

Abstract:
1. A method of heat-treating titanium aluminide alloy, the titanium aluminide alloy having a single alpha phase field and being capable of producing a massively transformed gamma microstructure, the titanium aluminide alloy comprises at least 45 at % aluminium, 0-6 at % niobium, 4-10 at % tantalum, niobium plus tantalum is less than or equal to 10 at % and the balance titanium and incidental impurities, the method comprising the steps of: (a) heating a titanium aluminide alloy to a temperature above the alpha transus temperature, (b) maintaining the titanium aluminide alloy at a temperature above the alpha transus temperature in the single alpha phase field for a predetermined time period, (c) cooling the titanium aluminide alloy at a cooling rate of 4° C.s (d) heating the titanium aluminide to a temperature below the alpha transus temperature in the alpha and gamma phase field, (e) maintaining the titanium aluminide at the temperature below the alpha transus temperature for a predetermined time period to precipitate alpha plates in the massively transformed gamma microstructure such that a refined microstructure is produced, (f) cooling the titanium aluminide to ambient temperature.