BORON CARBIDE CERMET STRUCTURAL MATERIALS WITH HIGH FLEXURE STRENGTH AT ELEVATED TEMPERATURES

摘要

Prepare boron carbide-aluminum structural composites by infiltrating molten aluminum or aluminum alloy into a porous preform that is either unbaked or baked at a temperature of up to 1800° C. to form a densified cermet and then heat treat the cermet in air or an oxygen- containing atmosphere to form a dense outer surface layer of aluminum oxide. The resulting structural cermets can withstand prolonged exposure to temperatures above the melting point of aluminum without suffering undue degradation of physical properties such as flexure strength.