BORON-CARBIDE-ALUMINUM AND BORON-CARBIDE-REACTIVE-METAL COMPOSITIONS AND METHODS FOR THE PRODUCTION THEREOF

摘要

Hard, tough, lightweight boron-carbide-reactive metal composites, particularly boron-carbide-aluminum composites, are produced. These composites have compositions with a plurality of phases. A method is provided, including the steps of wetting and reacting the starting materials, by which the microstructures in the resulting composites can be controllably selected. Starting compositions, reaction temperatures, reaction times, and reaction atmospheres are parameters for controlling the process and resulting compositions. The ceramic phases are homogeneously distributed in the metal phases and adhesive forces at ceramic-metal interfaces are maximized. An initial consolidation step is used to achieve fully dense composites. Microstructures of boron-carbide- aluminum cermets have been produced with modulus of rupture exceeding 110 ksi and fracture toughness exceeding 12 ksi{square root}in. These composites and methods can be used to form a variety of structural elements.