Development of Filament Reinforced Titanium Alloys

Titanium and its alloys can be used successfully as matrix material for continuous filaments, such as boron or silicon carbide. The single limiting factor in fabrication and life of the composites is the interaction between filament and matrix. Several attempts have been made to manufacture filament-reinforced titanium alloys; however, methods such as powder metallurgy, creep controlled diffusion bonding, and plasma arc spraying have been unsuccessful because interaction has led to reaction layers in excess of 1 micron in thickness. Compound thicknesses of such magnitudes render composites useless because cracks form in the compound at low strains and cause subsequent failure of the filaments. Recent developments in manufacturing techniques have made it possible to control formation of boride or sili-cide so that prolonged life is obtained. This paper describes properties of such composites.