Method for preparing sintered Nd-Fe-B alloy magnetic material

Abstract

This invention discloses a sintered NdFeB alloy magnetic materials preparation methods, the method is the weight of the shares in the 100 Nd-Fe-B alloy powder to add 0.01 to 0.2 in antioxidants, mixed after ground into a uniform particle size 2.8 - 4.5 mu m powder; good Nd-Fe-B powder in the mill to add 0.01 to 0.5 in the lubricant, argon or nitrogen, under the protection of uniform mixing obtained magnetic; will magnetic suppression after forming and sintering heat treatment, access to the final product . This invention in the Nd-Fe-B magnets milling through the process of adding antioxidants, in the process of accession lubricant mixture, in the suppression of the Nd-Fe-B magnetic particle forming process, the magnetic field intensity in the same circumstances raise powder orientation, thereby improving Magnetic products if the production is the same as the magnetic properties of magnets, we can reduce the forming pressure and time, so that get more capacity and reduce costs.

Description

technical field [0001] The invention relates to the technical field of preparation of sintered magnetic materials, in particular to a preparation method of a sintered NdFeB alloy magnetic material. Background technique [0002] In recent years, the average annual growth rate of NdFeB output in the world has reached 25%, and the growth rate in my country has reached 40%. Therefore, since 2001, my country has surpassed Japan and become a major producer of NdFeB magnets. In 2004, the output accounted for more than 60% of the world's total output, and it still maintains a strong growth momentum. However, compared with foreign countries, there are still many gaps in the magnet performance of rare earth permanent magnet materials in my country. Although the output of NdFeB in my country exceeds that of Japan, the output value is less than 1 / 2 of that of Japan, and the price of the product is only 1 / 3 to 1 / 2 of the international market due to the low magnetic properties of the mag...

AI Technical Summary

Problems solved by technology

[0004] However, after fully analyzing the production process of NdFeB magnets, it can be found that there are two problems in the production process: First, because NdFeB permanent magnet powder contains about 30% of rare earth elements, it is very easy to oxidize and be affected by moisture; Second, during orientation molding, the fluidity of NdFeB magnetic powder is poor, which affects its uniform dispersion after entering the mold cavity, as well as the rotational orientation and density of magnetic powder during forming.