carbonitrides

Carbonitrides are chemical compounds that contain both carbon and nitrogen, typically in combination with a metallic element. They often occur as transition metal carbonitrides, such as titanium carbonitride (Ti(C,N)), vanadium carbonitride (V(C,N)), and related solid solutions that interpolate between the corresponding carbides and nitrides (TiC–TiN, VC–VN, etc.). In these materials, carbon and nitrogen atoms occupy interstitial sites within a close-packed metal lattice, creating non-stoichiometric, tunable compositions.

Synthesis and forms are diverse. They can be produced by carburizing or nitriding processes, or by deposition techniques such as chemical vapor deposition and physical vapor deposition to form coatings. In cemented carbides and hard coatings, TiCN is a commonly used hard phase that complements tungsten carbide (WC) and cobalt binders, enhancing hardness and wear resistance. In steel surface engineering, carbonitriding introduces carbon and nitrogen to the surface to form Fe(C,N) phases and related precipitates, improving surface hardness and fatigue properties.

Properties of carbonitrides include high hardness, high melting points, and good wear and chemical resistance. The exact properties depend on the metal and the carbon-to-nitrogen ratio, with non-stoichiometric compositions offering a range of hardness, toughness, and thermal stability. Their performance can be tailored for specific applications by adjusting elemental content and microstructure.

Applications are broad in advanced manufacturing. They are used in cutting tools, wear-resistant coatings, drilling and milling components, and surface-engineered parts where a combination of hardness and toughness is required. Carbonitrides thus play a key role in cutting performance and tool longevity, often as components of composite materials or protective coatings.