Reaction Processing and Properties of Sic-To-Sic Joints

Abstract

AbstractReaction processing methods have been developed for fabricating SiC-to-SiC joints that can be used in elevated temperature applications. Processing steps include tape casting thin sheet SiC+C interlayer precursors, clamping the tape between the ceramic parts, providing a source of Si adjacent to the joint, and heating above the melting point of Si in argon. Molten Si infiltrates the tape via capillary action forming a reaction bonded silicon carbide (RBSC) interlayer and simultaneously joining the ceramic parts. Four-point bending strength and fracture toughness of joined pressureless sintered α-SiC test specimens have been evaluated at room and elevated temperatures. At low temperatures the joint mechanical properties were comparable to those reported for bulk SiC, while at elevated temperatures the joint properties were characteristic of the RBSC interlayer.