Cermets

Cermets are ceramic–metal composite materials designed to combine the hardness and wear resistance of ceramics with the toughness and processability of metals. In a typical cermet, a ceramic hard phase such as titanium carbide (TiC), tantalum carbide (TaC), niobium carbide (NbC), tungsten carbide (WC), aluminum oxide (Al2O3), or silicon carbide (SiC) is dispersed within a metallic binder, commonly nickel, cobalt, iron, or copper, or their alloys. The resulting microstructure features ceramic grains embedded in a metal matrix, which improves toughness relative to conventional ceramics.

Most cermets are produced by powder metallurgy. Ceramic and metal powders are mixed, shaped, and sintered at high temperature in a controlled atmosphere to promote bonding between phases while minimizing porosity. Hot pressing or hot isostatic pressing are often used to achieve a dense, uniform microstructure. Emerging manufacturing approaches, including certain additive manufacturing techniques, are being explored to broaden design possibilities.

Key properties of cermets include high hardness and excellent wear resistance, good high-temperature strength, and enhanced fracture toughness compared with monolithic ceramics. They also tend to have better thermal shock resistance and machinability than pure ceramics, though their performance depends on the chosen ceramic phase and binder. Cermets can be more expensive and processing-specific than traditional metals or ceramics, and their oxidation resistance at very high temperatures may limit some applications.

Applications are concentrated in situations requiring sharp, durable cutting tools and wear parts, such as cutting inserts for metalworking, dies and wear-resistant components in challenging environments, and components that benefit from a balance of hardness and toughness. The term “cermet” is often contrasted with cemented carbides; together they occupy a family of ceramic–metal composites designed for demanding engineering uses.