Chromaluminizing

Chromium aluminizing is a thermochemical process for the surface finishing of metals in which the surface of a workpiece is simultaneously enriched with chromium and aluminium. The aim of the process is to improve the high-temperature resistance, oxidation resistance and corrosion resistance of metals, particularly steels and nickel-based alloys. This process is often used in aerospace, gas turbines and other applications where components are exposed to extreme temperatures and aggressive environments.

In chromium aluminizing, the workpiece is embedded in a powdered mixture of chromium, aluminum compounds and activators (e.g. halides). This mixture is heated in a reaction furnace, typically to temperatures between 900 and 1100 °C. During the process, chromium and aluminum atoms diffuse into the surface of the workpiece and form protective intermetallic compounds such as chromium aluminides.

The resulting layer is highly resistant to oxidation and corrosion, as a dense and stable oxide layer of chromium and aluminum oxides forms at high temperatures. This oxide layer protects the underlying material from further chemical attack and prevents the progression of corrosion or oxidation.

Chromaluminizing is a highly specialized process that requires careful process control to ensure uniform layer formation and optimal properties. It is a durable and effective solution for the protection of components that are operated under extreme conditions.