Method for improving rare earth permanent magnet coercive force

Abstract

The invention discloses a method for improving coercive force of a rare-earth permanent-magnet, which is characterized in that in the process of manufacturing the rare-earth permanent-magnet, other rare-earth oxides except DyO and TbO are added into and fully mixed with prepared powdered alloy, and then the mixture is molded in an oriented way and sintered; and the added rare-earth oxides are NdOand / or GdO, and are treated by dehydration at the temperature of over 500 DEG C, and the doping proportion is 0.8-3.2% of the weight of the prepared powdered alloy. The rare-earth oxides with lower price are added into the prepared powdered alloy, and other processes are not changed, serial tests prove that when about 0.8% of rare-earth oxides are added, the coercive force is increased by 1900-3900KOe, and the remanence of the product is reduced by 200-300Gs. When the adding proportion is more than 1.6%, the remanence of the product is reduced, and the significance is significantly lowered. The method has simple technique, lower cost and remarkable effect.

Description

technical field [0001] The invention relates to a manufacturing method of a rare earth permanent magnet, in particular to a method for increasing the coercive force of the rare earth permanent magnet. Background technique [0002] At present, there are four mechanisms for increasing the Hcj elements of rare earth permanent magnets: one is to increase the anisotropy of the main phase, such as adding heavy rare earth metals Dy, Tb, etc.; the other is to refine the particle size of the main phase and improve the effective boundary. Quantity, usually by adding Al, Ga, Nb, Cu, Zr, etc. in the process of alloy smelting; the third is metal oxides that are beneficial to the boundary pinning effect and reduce the possibility of sintering main phase crystal growth, the boundary of the main phase Pinning, such as adding DyO, TbO, etc. to the alloy powder, the fourth is to add special metal powder to the alloy powder, so that the metal elements that are beneficial to improve the coerciv...

AI Technical Summary

Problems solved by technology

These methods all add the above-mentioned elements in the process of alloy powder smelting, and these elements are expensive, resulting in high prices of permanent magnet materials produced and lack of competitiveness

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