SPARK PLASMA SINTERING AND SELF-PROPAGATING HIGH-TEMPERATURE SYNTHESIS OF ULTRA-HIGH TEMPERATURE CERAMICS Hf – C

The future of the aerospace industry is directly related to the development and modernization of the heat-loaded components of hypersonic aircraft: jet engines, nose tips and sharp leading edges of the wings, which are required to withstand ultrahigh temperatures (above 2000°C) caused by aerodynamic heating. The greatest practical interest for the aerospace industry is centered around ultra-high temperature ceramics based on borides, nitrides, carbides, carbonitrides and double transition metal carbides [1–4]. These materials have unique physical and chemical properties. They are characterized by unparalleled combination of heat resistance, thermal conductivity, refractoriness (melting points above 3000°C), hardness, as well as electrical and thermal properties close to those of metals [5–9]. According to recent publications, hafnium carbonitride of optimum composition not only has good mechanical properties and high thermal conductivity, but also is believed to have the highest melting point (above 4200°C) among all currently existing systems. This peak refractoriness is explained by several factors affecting the melting point: the presence