alumised

Alumised is a term used to describe a surface that has been coated with aluminum or an aluminum-containing alloy, typically through a process called aluminization or aluminizing. The objective is to enhance surface properties such as oxidation resistance, wear resistance, and thermal performance, especially at elevated temperatures.

Common methods include hot-dip aluminizing, where parts are immersed in molten aluminum and then cooled to form a diffusion and intermetallic layer with the substrate; pack aluminizing, which uses aluminum-containing powders in a cementation pack to diffuse aluminum into the base metal; and thermal spray aluminizing, which applies a sprayed aluminum coating. Diffusion-based approaches such as aluminide coatings formed by chemical vapor deposition or diffusion processes can also be described as aluminised surfaces. The chosen method affects coating thickness, adhesion, and the nature of the aluminum-substrate interface.

Materials typically treated include steel and iron alloys, with aluminum or aluminum-rich coatings forming a protective barrier that slows oxidation and corrosion. Magnesium and some high-temperature alloys may also be aluminized under specific processes.

Applications are found in high-temperature and corrosive environments, including automotive exhaust components, heat exchangers, petrochemical equipment, and certain aerospace and industrial components. The coating offers protection by forming a stable aluminum oxide scale during service.

Limitations include potential coating brittleness, diffusion-controlled growth that can induce distortion, and adhesion issues if substrate preparation is inadequate. Quality control often involves coating thickness measurement, microstructural inspection, and corrosion testing to verify performance against specifications. See also aluminization and aluminide coatings.