Cermet — ceramic–metal composite materials

Key characteristics

Cermets aim to balance hardness, wear resistance, and ductility. As a class they are a kind of composite: the dispersed ceramic provides compressive strength and thermal stability while the metal phase offers fracture toughness, some ductility and the ability to conduct heat or electricity. Many cermets resist mechanical stress and show low surface friction, making them suitable where sliding contact and wear are concerns.

Manufacture and structure

Production commonly uses powder metallurgy: ceramic and metal powders are mixed, compacted and sintered so the metal wets and bonds ceramic grains. Variations include infiltration, hot pressing and advanced sintering techniques to control porosity and phase distribution. Microstructure — size, shape and continuity of each phase — determines performance: a continuous metal network improves toughness, while continuous ceramic networks boost hardness and thermal stability.

Uses and examples

Cermets are used in cutting tools, wear parts, engine components, and some high‑temperature structural applications. Their combination of properties also suits electrical contacts and thermal shields. Specific compositions are tailored to need: some prioritize wear resistance for machining, others emphasize thermal and chemical stability for aerospace or chemical processing.

Distinctions and notable points

Although sometimes grouped with cemented carbides such as tungsten‑based grades, cermets are a broader category. They differ from metal‑matrix composites and ceramic‑matrix composites by which phase is dominant and the intended balance of properties. Designers choose cermets when a hybrid of ceramic hardness and metal toughness gives an advantage over monolithic ceramics or metals.

Further reading and technical summaries are available from material databases and manufacturing references; specialized sources discuss specific chemistries and processing routes in detail. For a general introduction to related material classes see entries on ceramics, metals and industrial composites.