Heat resistant plastic magnets

A new SmFeN plastic magnet that has the heat resistance of 473 K was developed. In order to achieve high heat resistance, the surface treatment of the SmFeN powder was carried out by Zn, and a resin called PBN was chosen. By the Zn treatment, powder coercivity went up from 1040 kA/m to 1600 kA/m. Moreover, since the melting point of PBN resin was 516 K, we could make a heat resistant plastic magnet, keeping process temperature at 573 K or less.