Nitridoituminen

Nitridoituminen, the Finnish term for nitridation, refers to the chemical process in which nitrogen atoms are introduced into the crystal lattice of a solid material, typically a metal or alloy. The process can occur through various methods such as gas nitriding, plasma nitriding, or ion implantation, each employing different sources of nitrogen and varying temperature and pressure regimes. In gas nitriding, a nitrogen‑containing atmosphere (often a mixture of hydrogen and nitrogen) is exposed to a heated substrate, allowing nitrogen atoms to diffuse into the surface layers. Plasma nitriding uses a glow discharge to generate active nitrogen species at lower temperatures, whereas ion implantation bombards the material with high‑energy nitrogen ions, creating a highly concentrated nitrogen layer.

Practically, nitridoituminen is employed to enhance surface hardness, wear resistance, and corrosion resistance while preserving the core properties of the substrate. It is widely used in the automotive, aerospace, and machining industries where improved fatigue life and reduced maintenance are critical. The technique also finds application in semiconductor fabrication, where controlled nitrogen incorporation can modify electronic properties of silicon or compound semiconductors.

From a crystallographic standpoint, the introduction of nitrogen may lead to the formation of solid solution phases or interstitial nitrides, depending on the material system and processing conditions. Typical characteristics include a hardened surface layer a few micrometres thick, a reduced residual stress compared with carburiding, and the possibility to tailor phase transformations in the heat‑treated matrix.

The terminology originates from the traditional English word “nitridation,” but has been integrated into Finnish technical literature since the early 20th century, expanding to include not only traditional nitriding but also advanced plasma‑assisted processes that have become standard in modern surface engineering.