Thermal properties of injection molded dielectromagnets

摘要

Injection molded dielectromagnets are permanent magnets made by injection molding from hard magnetic powders bonded by binder. Applications of dielectromagnets depend mainly on their magnetic, thermal and mechanical properties. Thermal properties have a significant influence on their application, as they work very often at high temperatures. Thermal properties of permanent magnets are expressed by the temperature coefficent of coercivity and remanence and depend mainly on the kind of hard magnetic powders used. Dielectromagnets from melt-spun ribbon Nd-Fe-B have high magnetic properties, but their weakness is their temperature coefficent of coercivity. In opposition are dielectromagnets from ferrite powders. They have low magnetic properties, but a positive value of the temperature coefficent of coercivity - coercivity increases with increasing temperature. The purpose of this investigation is to develop injection molded dielectromagnets from a mixture of hard magnetic powders with good magnetic and thermal properties.