US 11,731,193 B2
Preparation method of improved sintered neodymium-iron-boron (Nd—Fe—B) casting strip
Yu Wang, Inner Mongolia (CN); Feng Xia, Inner Mongolia (CN); Caina Sun, Inner Mongolia (CN); Yonghuai Feng, Inner Mongolia (CN); Yanli Li, Inner Mongolia (CN); Jiao Gao, Inner Mongolia (CN); and Jixiang Liu, Inner Mongolia (CN)
Assigned to BAOTOU JINSHAN MAGNETIC MATERIAL CO., LTD., Inner Mongolia (CN)
Filed by Baotou Jinshan Magnetic Material Co.,Ltd., Inner Mongolia (CN)
Filed on Jun. 28, 2021, as Appl. No. 17/360,540.
Claims priority of application No. 202110036074.0 (CN), filed on Jan. 12, 2021.
Prior Publication US 2022/0219228 A1, Jul. 14, 2022
Int. Cl. B22D 21/02 (2006.01); H01F 1/057 (2006.01); H01F 7/02 (2006.01); H01F 41/02 (2006.01); C22B 9/16 (2006.01)
CPC B22D 21/025 (2013.01) [H01F 1/0577 (2013.01); H01F 7/02 (2013.01); H01F 41/0253 (2013.01); C22B 9/16 (2013.01)] 9 Claims
OG exemplary drawing
 
1. A method for preparing a sintered Nd—Fe—B casting strip, the method comprising the following steps:
1) preparing nucleation assisted alloy particles used for the sintered Nd—Fe—B casting strip;
1.1) weighing the following nucleation assisted alloy particle elements: 26.68-28 wt % of Pr—Nd, 70-72.5% of Fe and 0.90-1% of B, wherein a Pr element in two elements of Pr—Nd accounts for 0-30 wt %, and obtaining an alloy strip with a proportion of ingredient atoms close to that of (Pr—Nd)2Fe14B through conventional compounding, smelting and pouring; and
1.2) crushing the alloy strip into particles with a diameter in the range from 1-10 mm, to serve as the nucleation assisted alloy particles used for the sintered Nd—Fe—B casting strip;
2) preparing the sintered Nd—Fe—B casting strip;
2.1) providing an intermediate material, wherein composition of the intermediate material is calculated according to the composition of the Nd—Fe—B casting strip to be prepared and an additional quantity of the nucleation assisted alloy particles, and the additional quantity of the nucleation assisted alloy particles is in the range from 3-6% by weight, based on a total weight of the sintered Nd—Fe—B casting strip; and
2.2) melting the intermediate material and smelting for 10-20 minutes to obtain a smelted intermediate material, adding the nucleation assisted alloy particles into the smelted intermediate material, further smelting for 3-15 minutes under a condition that power is reduced by 150-250 KW from a power for smelting the intermediate material, and pouring, thereby obtaining the sintered Nd—Fe—B alloy casting strip.