Carbonitridit

Carbonitridit is a term used in metallurgy and materials science to describe compounds and surface layers that contain both carbon and nitrogen in combination with a metal or ceramic matrix. In English the closest term is carbonitride, and carbonitridit is used in several European languages to designate metal carbonitrides and diffusion-formed carbonitride surfaces.

Metal carbonitrides are interstitial compounds in which carbon and nitrogen occupy interstitial sites in a metal lattice, forming solid solutions such as Me(C,N). Common examples include titanium carbonitride (TiCN) and niobium carbonitride (Nb(C,N)). The carbon-to-nitrogen ratio can vary, yielding phases with different hardness, modulus, and thermal stability.

Carbonitridit-related materials are widely produced by deposition or diffusion processes. Coatings for tools and wear parts are often made by physical vapor deposition (PVD) or chemical vapor deposition (CVD), sometimes in multilayer or doped configurations with nitrides or carbides. Diffusion-based carbonitriding of steel introduces carbon and nitrogen into the surface to form hard Fe(C,N)-containing layers.

Properties of carbonitrides include high hardness and wear resistance, good chemical stability, and, for some compositions, elevated temperature performance. Applications include cutting tools, milling inserts, dies, and wear-resistant components. Processing conditions, such as temperature, gas composition, and alloying elements, determine the balance between hardness, toughness, and brittleness.

History and usage: The concept has been developed in the 20th century as part of tool coating technology and surface hardening. Carbonitrides are widely used in industry for extended tool life and reliability. Safety and cost considerations influence selection and deposition methods.