Method for manufacturing rare earth sintered magnet using pre-sintering process

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According to the present invention, a method for manufacturing a rare earth sintered magnet using a pre-sintering process comprises the steps of : (a) preparing an R-Fe-B-based magnet powder (where R is a rare earth element or a combination thereof); (b) heating the magnet powder to preset pre-sintering temperature to pre-sinter the magnet powder; (c) surface-coating a coating solution including a rare earth compound or a rare earth alloy powder on the generated pre-sintered magnet; and (d) heating the pre-sintered magnet to post-sintering temperature relatively higher than the pre-sintering temperature to post-sinter the magnet. In the method for manufacturing the rare earth sintered magnet using the pre-sintering process of the present invention, a pre-sintering process sintered at relatively low temperature compared to a sintering process is performed as a pre-process of the sintering process. Also, the rare earth element is coated on a surface of the pre-sintered magnet so as to be diffused, Thereby a content of the rare earth element added to the sintered magnet. Further, the rare earth element can be efficiently diffused in a thickness direction along a pore or a grain boundary in the sintered magnet, thereby improving the coercive force of the sintered magnet.