A Tough, Thermally Conductive Silicon Carbide Composite with High Strength up to 1600°C in Air

Abstract

A sintered silicon carbide fiber–bonded ceramic, which consists of a highly ordered, close-packed structure of very fine hexagonal columnar fibers with a thin interfacial carbon layer between fibers, was synthesized by hot-pressing plied sheets of an amorphous silicon-aluminum-carbon-oxygen fiber prepared from an organosilicon polymer. The interior of the fiber element was composed of sintered β-silicon carbide crystal without an obvious second phase at the grain boundary and triple points. This material showed high strength (over 600 megapascals in longitudinal direction), fibrous fracture behavior, excellent high-temperature properties (up to 1600°C in air), and high thermal conductivity (even at temperatures over 1000°C).