Microcomposite of metal boride and ceramic particles

Claim 1

A process for producing a polycrystalline microcomposite consisting essentially of a continuous interconnecting phase of a boride of a metal selected from the group consisting of hafnium, niobium, tantalum, titanium, vanadium, zirconium and mixtures thereof and a phase of ceramic particles, said phases being distributed at least significantly uniformly in said microcomposite, said microcomposite having a density greater than 95% of the theoretical density for said microcomposite, which consists essentially of forming a particulate mixture of boron, a hydride of a metal selected from the group consisting of hafnium, niobium, tantalum, titanium, vanadium, zirconium and mixtures thereof, and a ceramic powder, hot pressing the particulate mixture under a pressure of at least about 200 psi at a temperature ranging from about 1200° C. to about 2000° C. decomposing said hydride of said metal producing said metal and by-product gas which vaporizes away and reacting said metal with said boron producing the boride of said metal as a continuous interconnecting phase, said continuous metal boride phase encapsulating at least about 20% by volume of said ceramic particles and either encapsulating or being intermixed with the balance of said ceramic particles, said process having no significant effect on said ceramic particles, said continuous interconnecting metal boride phase ranging from about 20% by volume to about 80% by volume of said microcomposite and the balance of said microcomposite consisting essentially of particles of said ceramic.