REACTION SINTERING PHENOMENA OF SELF-PROPAGATING HIGH-TEMPERATURE SYNTHESIS-DERIVED CERAMIC POWDERS IN THE TI-SI-C SYSTEM

摘要

Sintering phenomena of self-propagating high-temperature synthesis (SHS)-derived powders often have a character of densification accompanied by a reaction in solid and/or liquid phase. The problem is discussed in the case of preparation of Ti3SiC2-based materials. This novel laminate ceramics has some unique properties like low hardness, high fracture toughness, corrosion resistance and ductile character at elevated temperature. Because of specific mechanisms during rapid combustion-type SHS reactions, it is possible to prepare Ti3SiC2-rich powders that can be used as precursors for preparation of Ti3SiC2-based polycrystals. Densification of these powders occurs with formation of transient metallic liquid phase. As a result, dense polycrystals with controlled microstructures in form of particulate composites with Ti3SiC2 matrix and controlled TiC inclusions can be obtained. The reactions occurring during preparation of Ti3SiC2-based composites with WC and B4C are also discussed. [References: 17]