Abstract: A gamma titanium aluminide alloy consisting of 46 at % aluminium, 8 at % tantalum and the balance titanium plus incidental impurities has an alpha transus temperature T? between 1310° C. and 1320° C. The gamma titanium aluminide alloy was heated to a temperature T1=1330° C. and was held at T1=1330° C. for 1 hour or longer. The gamma titanium aluminide alloy was air cooled to ambient temperature to allow the massive transformation to go to completion. The gamma titanium aluminide alloy was heated to a temperature T2=1250° C. to 1290° C. and was held at T2 for 4 hours. The gamma titanium aluminide alloy was air cooled to ambient temperature. The gamma titanium aluminide alloy has a fine duplex microstructure comprising differently orientated alpha plates in a massively transformed gamma matrix. The heat treatment reduces quenching stresses and allows larger castings to be grain refined.

Abstract: A component can be formed by a hot isostatic pressing (HIP) process but it is necessary to reinforce intricate internal structures against collapse and deformation by the hot isostatic pressing process. The present method utilizes a low melting point salt or alloy reinforcement within the structure which can be released when molten through a drain from the internal structure. The reinforcement may be molten as a result of the hot isostatic process or through achieving a temperature with the component which causes the reinforcement to become molten but without damaging the component itself. The remaining parts of the reinforcement may be removed by use of a solvent or simple washing with a corrosive agent to remove any reinforcement debris.

Abstract: A method of treating a titanium aluminide alloy having a single alpha phase field and being capable of producing a massively transformed gamma microstructure by subjecting the alloy to a temperature cycle that produces the massively transformed microstructure having a refined microstructure; the method being characterised in that oxygen securing means are provided within the alloy to prevent diffusion of oxygen to the grain boundary.

Abstract: A gamma titanium aluminide alloy consisting of 46 at % aluminium, 8 at % tantalum and the balance titanium plus incidental impurities has an alpha transus temperature T? between 1310° C. and 1320° C. The gamma titanium aluminide alloy was heated to a temperature T1=1330° C. and was held at T1=1330° C. for 1 hour or longer. The gamma titanium aluminide alloy was air cooled to ambient temperature to allow the massive transformation to go to completion. The gamma titanium aluminide alloy was heated to a temperature T2=1250° C. to 1290° C. and was held at T2 for 4 hours. The gamma titanium aluminide alloy was air cooled to ambient temperature. The gamma titanium aluminide alloy has a fine duplex microstructure comprising differently orientated alpha plates in a massively transformed gamma matrix. The heat treatment reduces quenching stresses and allows larger castings to be grain refined.

Abstract: A component can be formed by a hot isostatic pressing (HIP) process but it is necessary to reinforce intricate internal structures against collapse and deformation by the hot isostatic pressing process. The present method utilises a low melting point salt or alloy reinforcement within the structure which can be released when molten through a drain from the internal structure. The reinforcement may be molten as a result of the hot isostatic process or through achieving a temperature with the component which causes the reinforcement to become molten but without damaging the component itself. The remaining parts of the reinforcement may be removed by use of a solvent or simple washing with a corrosive agent to remove any reinforcement debris.

Abstract: An assembly for manufacture of a component by hot isostatic pressing comprises a first workpiece and a second workpiece. The first workpiece and second workpiece are assembled to define a cavity. Removable tooling pieces are provided to the assembly which further define the cavity and which are shaped to apply a forging load to a powder within the cavity during hot isostatic pressing.

Abstract: A gamma titanium aluminide alloy consisting of 46 at % aluminium, 8 at % niobium, up to 0.07 at % carbon and the balance titanium plus incidental impurities has an alpha transus temperature T?=1335° C. The gamma titanium aluminide alloy was heated to a temperature T1=1360° C. and was held at T1=1360° C. for 1 hour or longer. The gamma titanium aluminide alloy was fluidised bed, or salt bath, quenched to a temperature T2, where 900° C.<T2<1200° C., and was held at temperature T2 for a sufficient time to allow the massive transformation to go to completion. The gamma titanium aluminide alloy was heated to a temperature T3=1300° C. or 1320° C. and was held at T2 for 4 hours. The gamma titanium aluminide alloy was air cooled to ambient temperature. The gamma titanium aluminide alloy has a fine duplex microstructure comprising differently orientated alpha plates in a massively transformed gamma matrix.