Combustion synthesis of ultra-high temperature ceramics: Review

Novel and future-oriented aerospace, energy, transportation, and other industrial technologies require materials capable of operating at temperatures above 2000°C. Ultra-high temperature ceramic materials (UHTCs), based on carbides, borides, carbonitrides, and nitrides of transition metals—many with melting points exceeding 3000°C—possess the necessary properties for such applications. However, traditional powder metallurgy methods for producing these materials are complex, energy-intensive, and typically require ultra-high temperature equipment. The combustion synthesis (CS) method, also known as self-propagating high-temperature synthesis (SHS), offers a rapid and efficient alternative. It leverages the exothermic heat generated during chemical reactions to produce UHTCs without external heating sources. This review discusses the achievements of CS in synthesizing a wide range of UHTCs—from simple compounds to complex, multicomponent “high-entropy” ceramics—including materials with record-breaking melting points based on carbonitrides, binary carbides, and diborides. There are two primary approaches to producing dense UHTCs: (1) CS of ultra-refractory powders followed by compaction using hot pressing or spark plasma sintering, and (2) simultaneous synthesis and compaction via reactive spark plasma sintering. Overall, the CS method opens exciting prospects for developing advanced materials that meet the demanding requirements of modern industry.