Patent ID: 6863742

Claim:
A method for preparing a bulk anisotropic rare earth permanent magnet, comprising the steps of: placing in a magnetic field of at least 800 kA/m a rare earth magnet powder consisting essentially of R, Fe or Fe and Co, and N, wherein R is selected from rare earth elements inclusive of Y and contains Sm as a main component, and having a primary phase of Th 2 Zn 17 crystal structure, so that C-axis is oriented in the magnetic field direction, and monoaxially hot pressing the powder into a bulk body while heating the powder to the highest temperature within a time of 2 seconds to 5 minutes to provide a heated bulk body; and cooling the heated bulk body to below 300° C. within a time of 5 seconds to 10 minutes, thereby obtaining a bulk anisotropic rare earth permanent magnet consisting essentially of R, Fe or Fe and Co, and N, wherein R is selected from the rare earth elements inclusive of Y and contains Sm as a main component and having a primary phase of Th 2 Zn 17 crystal structure, a density of at least 90% of the true density and unidirectionally oriented C-axis.