Role of Silicon in PM Processed Soft Magnetic Alloy
Iron-Phosphorus based soft magnetic materials are known for their hot and cold shortness. The present investigation deals with the development of high-density Fe-P based alloys in the form of very thin sheets (0.1mm) by proper soaking of them at a high temperature so as to eliminate Iron-Phosphide eutectic and bring the phosphorus entirely into solution in the iron. It has also been possible to eliminate the use of a hydrogen atmosphere during sintering by using carbon to form CO gas within the compact by reaction with the oxygen of the iron powder particles. A glassy ceramic coating applied over the compact serves as a protective coating in order to avoid atmospheric oxygen attack over the compact held at high temperature. The Fe-0.3wt% P- 0.4wt% Si alloy so formed yielded coercivities as low as 0.42 Oe, resistivities as high as 28.4 µΩcm and total losses as low as 0.132 W/Kg. Such a combination of properties may make the alloy suitable for application in magnetic relays and transformer cores.
David J. Fisher
D. Sharma et al., "Role of Silicon in PM Processed Soft Magnetic Alloy", Defect and Diffusion Forum, Vol. 307, pp. 13-19, 2010