Method of preparing samarium iron nitrogen permanent amgnet material using mechanical alloying

A technology of mechanical alloying and permanent magnetic materials, applied in the direction of magnetic materials, magnetic objects, electrical components, etc., can solve the problems of nitrogen infiltration and retention, high cost, complicated SmFeN process, etc., to achieve good magnetic properties, low cost, easy-to-handle effects

Inactive Publication Date: 2005-05-18
UNIV OF SCI & TECH BEIJING
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0009] The purpose of the present invention is to provide a method for preparing SmFeN permanent magnet materials by mechanical alloying method, which solves the problems of complex process, difficulty in infiltrating and maintaining nitrogen, and high cost in the preparation of SmFeN.

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0015] Embodiment 1: with ammoniacal liquor (NH 3 ·H 2 O) Wet grinding for protective atmosphere

[0016] Raw materials: 25% by mass of Sm powder, 75% by mass of Fe powder.

[0017] Put the above-mentioned raw material powder into a stainless steel ball mill tank after mixing, the ball-to-material ratio (the ratio of the ball to the mixture) is 10:1, inject ammonia water into the ball mill tank, start the ball mill, and stop it every 10 minutes during the ball mill process, so that Cool down and check the machine, fill it with N after grinding 2 The nitrogen-containing Sm-Fe alloy powder is taken out into bags in the protected glove box. After ball milling for 2 hours, the N content (N content refers to the content of the total mass of combined N and adsorbed elemental N in the magnetic material) reaches 1.2% by mass, and the average particle size of the powder is 9 μm. Then the alloy powder is loosely packed and sintered at 400°C in an ammonia-decomposing atmosphere furna...

example 2

[0018] Example 2: Ball milling with nitrogen as medium

[0019] Raw material: 28% by mass of Sm powder, 72% by mass of Fe powder, and 0.3% by mass of Cr powder.

[0020] Mix the above-mentioned raw material powders and put them into a ball mill tank. The ball-to-material ratio (the ratio of balls to mixture) is 10:1. After the tank is evacuated, high-purity N 2 , start the ball mill, stop every 15 minutes during the ball milling process, in order to cool down and check the machine, after the grinding is completed, fill the N 2 The alloy powder was taken out from the protected glove box. After ball milling for 4 hours, the N content (N content refers to the content of the total mass of combined N and elemental N adsorbed in the material in the magnetic material) reached 1.4% by mass, and the average particle size of the powder was 7 μm. Then heat the alloy powder at 480°C in an ammonia-decomposing atmosphere furnace and keep it warm for 1 hour. The nitrogen content of the obt...

example 3

[0021] Example 3: Wet milling with liquid ammonia as the ball milling medium

[0022] Raw materials: 28% by mass of Sm powder, 72% by mass of Fe powder, and 1.5% by mass of Cr powder.

[0023] Mix the raw material powder and put it into the ball milling tank, the ball-to-material ratio (the ratio of balls to the mixture) is 10:1, after the ball milling tank is evacuated, inject liquid ammonia, start the ball mill, and stop every 15 minutes during the ball milling process , in order to cool down and check the machine, after the grinding is filled with N 2 The alloy powder was taken out from the protected glove box. After ball milling for 6 hours, the N content reached 1.8% by mass, and the average particle size of the powder was 4.5 μm. Then the alloy powder is loosely packed and sintered in an ammonia-decomposing atmosphere furnace at 500°C, and kept for 2 hours. The N content of the obtained magnetic powder reaches 3.6% by mass, and the magnetic performance is B r =1.1T, ...

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Abstract

The invention provides a method for preparing SmFeN permanent magnet material by mechanical alloying, which is characterized in that pure Sm powder and Fe powder are pressed by Sm 2 Fe 17 1-30% more Sm powder ratio is added, that is, the final mass percentage is 25-30% Sm, 70-75% Fe. In order to increase the infiltration amount of nitrogen, elements that can promote nitriding (such as Cr, Ni, Co, etc.) can also be added, and the mass percentage is about 0.1-2%. After preliminarily mixing the raw material powders, mill them in a high-energy ball mill for 1 to 20 hours. The milling medium is a nitrogen-containing substance. During the milling, stop for 5 to 20 minutes every 5 to 30 minutes to prevent the temperature in the tank from being too high. The invention has the advantages of high nitrogen content, compact structure, and the ability to prepare magnetic properties B r =1.3T, i h c =3390KA / m, (BH) m =395kJ / m 3 SmFeN magnetic powder and bulk material; and realize simple equipment, easy operation, high production efficiency and low cost.

Description

technical field [0001] The invention belongs to the technical field of preparing rare earth permanent magnet materials by powder metallurgy, and in particular provides a method for preparing samarium iron nitrogen permanent magnet materials by mechanical alloying. Background technique [0002] Research on high-performance iron-based rare earth permanent magnets has attracted attention this year. The successful development of NdFeB has inspired people to explore the magnetic properties of new ternary rare earth iron compounds. Among many new compounds, the prospect of SmFeN is the most promising. [0003] The data show that: with Th 2 Fe 17 Crystal structure of Sm 2 Fe 17 The Curie temperature is only 116°C, and the basal plane is anisotropic, but these Sm obtained by nitriding 2 Fe 17 N x But it becomes uniaxial anisotropy, and its Curie temperature Tc and saturation magnetization Ms have been greatly improved. The saturation magnetization reaches 1.54T, which is co...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): C22C1/04C22C29/16C22C33/02H01F1/059
Inventor 贾成厂尹法章关璐平延磊曲选辉
Owner UNIV OF SCI & TECH BEIJING
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