Poudres métalliques pour la production de pièces magnétiques douces

Metal powders for the production of soft magnetic parts

Höganäs AB, Höganäs (Suède)

Abstract

Soft magnetic parts for various applications are today being produced from iron powders. The soft magnetic properties can be steered by choice of iron powder, compacting pressure and sintering conditions. The primary factors to be considered when selecting an appropriate powder are purity, particle size and compactability, the addition of alloying elements broadens the area of application.

Pure iron powders such as ASC100.29 and ASC40.29 are basic materials which satisfy the criteria for soft magnetic parts in DC applications. The addition of alloying elements such as phosphorus, silicon and nickel shall be considered. Alloying with up to 0.8% phosphorus enhances the properties of materials for DC applications. The addition of silicon results in increased resistivity which is necessary for AC applications. Nickel must be introduced when short reaction times and saturation induction are required.

In the case of material requiring very high resistivity a binder in powder form can be added to the metal powder which after pressing and hardening at 150°C results in a product where the metal powder grains are insulated by the binder.

Through correct choice of material combined with well defined sintering conditions a variety of material can be produced which covers a broad application area.