Abstract: Ultra smooth ceramic materials are prepared by the low temperature sintering of a ceramic body that has been infiltrated prior to sintering with an inorganic polymer. The infiltration allows for a decrease in the sintering temperature which translates into a smoother, stronger ceramic material.

Abstract: Ceramic precursor mixtures containing a metal cation, a carbohydrate, and an anion capable of participating in an anionic oxidation-reduction reaction with the carbohydrate for continuous or batchwise drying and pyrolyzing to provide ceramic powders.

Abstract: A process for producing porous ceramics with controlled microstructure. Colloidal suspensions of polymeric microspheres of a selected size and shape, and aluminum oxide particles are consolidated to form a compact. The compact is heated to decompose the microspheres to leave pores, and to sinter the compact, to form a porous ceramic body with a plurality of pores preferably substantially the same size and shape, where the pores are substantially spherical and are evenly distributed and noncontiguous throughout the ceramic matrix and with strength comparable to its dense state.

Abstract: Low-density composites are produced consisting chiefly of boron carbide and aluminum, or aluminum alloy, and minor amounts of ceramic material. The method allows control of the rate of reaction between boron carbide and metal so that the final components of the composite, and hence the mechanical properties, are controlled. The invention includes modification of the carbon content of the boron carbide composition, dispersion of boron carbide and formation of a compact, infiltration of the compact by aluminum or aluminum alloy, and heat treatments. The invention produces low-density boron carbide-aluminum composites with a homogeneous microstructure possessing desired mechanical properties.

Abstract: 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.sqroot.in. These composites and methods can be used to form a variety of structural elements.