ironcobalt

Iron cobalt, often referred to as iron–cobalt or FeCo, is an alloy composed primarily of iron and cobalt. The term covers a family of alloys with cobalt content ranging from modest to high, chosen to tailor magnetic and mechanical properties for specific applications. Common variants include soft magnetic FeCo alloys used for transformer cores and sensors, as well as higher‑cobalt formulations aimed at improved hardness or elevated temperature performance. Small additions of elements such as vanadium, chromium, silicon, or aluminum may be included to enhance oxidation resistance, grain structure, or strength.

Properties of iron–cobalt alloys depend on composition. They generally exhibit high saturation magnetization and high Curie temperatures, enabling operation at elevated temperatures. Soft magnetic FeCo materials offer high permeability and low coercivity, which translate to low core losses in high‑frequency applications. Increasing cobalt content can raise hardness and tensile strength, but may reduce ductility. The microstructure—grain size, texture, and phase distribution—also strongly influences magnetic behavior and mechanical properties.

Production methods include vacuum arc remelting, induction melting, and powder metallurgy to achieve controlled microstructures and consistent properties. These processes allow precise control of cobalt content and the distribution of alloying elements.

Applications span electromagnetic devices and precision components. FeCo alloys are used in transformer and inductor cores, RF and high‑frequency magnetic components, magnetic sensors, and read/write heads. They also appear in certain hard magnets and thin‑film magnetic technologies. Cobalt-containing alloys require standard industrial hygiene practices due to cobalt’s toxicity in some forms and considerations about supply chain sustainability.