Abstract: The low peel strengths of diffusion bonded joints in aluminum alloy structures has been a bar to their use in superplastic forming. The invention overcomes this disadvantage by creating a workpiece intended for subsequent superplastic forming by diffusion bonded assembly of alloy sheets (30-32) in bonding zones according to a predetermined pattern and providing reinforcing material (33) in the workpiece in the region of the diffusion bonded zones. The reinforcing material serves to prevent the tensile stresses exerted during subsequent superplastic forming from initiating peel fracture of the diffusion bonds. Instead, the tensile stresses act so as to bring about superplastic deformation in those regions of the workpiece between the diffusion bonded zones.

Abstract: An alloy based on titanium and containing 0.5 to 30% by weight of magnesium, calcium or lithium is produced by vapor quenching to yield a metastable solid solution of solute in titanium. Exemplified alloys containing magnesium have age hardening or solution strengthening characteristics. Vapor quenching enables these alloys to be produced despite the differences in melting temperature between solute and solvent by separate vaporization of each of the species and mixing in the vapor phase. This method provides a route to achieving rapid solidification microstructures unobtainable by other rapid solidification methods. Preferred alloys comprise Ti with 1-15% or 3-7% by weight of magnesium. The alloys may contain other strengthening ingredients currently used in titanium alloys.

Abstract: Precursors for metal matrix composites are produced by coating a long fibre ceramic reinforcement with alternating layers of dissimilar species of matrix materials to an aggregate thickness sufficient to yield the intended matrix volume fraction in a consolidated product without additional material. This duplex coating of fibres is performed by vapor phase deposition comprising vapor condensation, sputtering or chemical vapor reaction. The precursor includes an aggregate coating of at least 5% of fibre diameter, preferably at least 20%. Various duplex systems are disclosed, each having one component significantly more frangible than the other to render damage tolerant properties to the resultant metal composite.Product materials are produced from the duplex matrix coated fibres by consolidation of an assembly of coated fibres under conditions of elevated temperature and pressure to cause inter-fibre matrix flow and bonding of matrix materials.

Abstract: A titanium based alloy compressor blade is given a wear-resistant portion such as a tip portion by producing an interfitting male/female joint between the blade and the wear-resistant portion in which the joint portion of the latter is produced with inwardly directed corrugations and the former is pressed at elevated temperature after assembly of the two parts so as to cause the material of the blade to flow into and conform to the shape of the latter and to produce a diffusion bond between the two parts. Interlayers may be used to improve chemical compatibility between the respective parts.