ceramicsmetal

Ceramicsmetal refers to composite materials that combine ceramic and metallic phases to exploit the advantageous properties of both constituents. The term is closely associated with cermets, which are hard, wear-resistant ceramic particles embedded in a ductile metal matrix. The goal is to marry the high hardness, high-temperature stability, and chemical resistance of ceramics with the toughness, ductility, and thermal conductivity of metals.

Composition and microstructure: Typical ceramic phases include tungsten carbide (WC), titanium carbide (TiC), silicon carbide (SiC), and aluminum oxide (Al2O3). These are dispersed in a metal matrix such as cobalt, nickel, nickel-chromium, or iron-based alloys. Microstructures can be dispersed-particle composites or core-shell configurations, and production methods vary from powder metallurgy and liquid-phase sintering to infiltration of molten metal into a porous ceramic preform.

Properties and performance: Ceramicsmetals generally show improved fracture toughness and resistance to crack propagation relative to monolithic ceramics, while maintaining substantial hardness and wear resistance. They can perform at elevated temperatures and offer good high-temperature strength. However, differences in thermal expansion between phases and limited intrinsic ductility can introduce residual stresses and complicate processing. Densities depend on the exact phases but are often higher than pure ceramics and lower than many metals.

Applications: The main use is wear-resistant tooling, especially cemented carbide cutting tools that combine WC particles with a metal binder. Additional applications include wear parts for high-temperature or harsh environments, machining components in aerospace, and other industrial components requiring a balance of hardness and toughness.

See also: cermet, metal matrix composite, ceramic matrix composite.