Continuous hydrogen decrepitation method for rare earth permanent magnetic alloy

Abstract

The invention provides a continuous hydrogen decrepitation method for a rare earth permanent magnetic alloy. The method is carried out in a continuous hydrogenation furnace provided with an activation chamber, a hydrogen absorption chamber, a first dehydrogenation chamber, a second dehydrogenation chamber and a cooling chamber. The continuous hydrogen decrepitation method comprises the following steps that the rare earth permanent magnetic alloy is activated in the activation chamber; selective hydrogen absorption is carried out in the hydrogen absorption chamber; circulating heating dehydrogenation is carried out in the first dehydrogenation chamber and the second dehydrogenation chamber; cooling is carried out, that is, forced cooling is carried out in the cooling chamber through argon. The heating dehydrogenation process in the first dehydrogenation chamber is divided into two stages; the temperature in the first stage ranges from 400 DEG C to 550 DEG C, and the temperature in the second stage ranges from 550 DEG C to 600 DEG C; the heating dehydrogenation process in the second dehydrogenation chamber is divided into two stages; and the temperature in the first stage ranges from 550 DEG C to 600 DEG C, and the temperature in the second stage ranges from 400 DEG C to 550 DEG C.

Description

technical field

[0001] The invention relates to a method for continuous hydrogen crushing of rare earth permanent magnet alloys. Background technique

[0002] The hydrogen crushing of rare earth metal-based magnetic materials is to use the hydrogen absorption characteristics of alloy ingots and strips to make them embrittled, so as to effectively prepare coarse powder in a short time, and then heat the coarse powder to 400 in vacuum or inert atmosphere. At ~600°C, part of the absorbed hydrogen is released.

[0003] At present, the commonly used NdFeB rare earth permanent magnet alloy hydrogen crushing production equipment is the rotary furnace gall type hydrogen crushing furnace, which adopts water cooling, the cooling speed is low, and there are great safety hazards, and the energy consumption of the externally heated muffle furnace is also low. Very big. In addition, it is very difficult to take out the magnetic powder from this rotary furnace type hydrogen breaking furn...

Examples

Embodiment 1

[0024] The chemical composition of NdFeB magnets is: 31.9% Nd, 1.0% Dy, 1.0% Co, 0.10% Cu, 0.12% Ga, 0.3% Nb, 0.97% B, and the rest is Fe.

[0025] The following steps are taken to prepare rare earth permanent magnets.

[0026] (1) Melting

[0027] Raw materials are prepared in proportion, melted in a 600Kg / time strip casting furnace (strip casting), and cast into scales to finally obtain strips with an average thickness of 0.3 mm.

[0028] (2) Hydrogen fragmentation

[0029] (3) jet mill

[0030] Micropowder with an average particle size of 2-4 μm is produced in a jet mill with nitrogen as the working gas.

[0031] (4) Compression molding

[0032] In a nitrogen-protected closed press, the micropowder is pressed into a compact when the orientation field is 1.4T, and the mold adopts a conventional non-magnetic steel mold.

[0033] (5) Sintering

[0034] Stack the green compacts in any way, and sinter them in a vacuum sintering furnace at 1075°C for 4 hours.

[0035] (6) ...

technical field

[0001] The invention relates to a method for continuous hydrogen crushing of rare earth permanent magnet alloys. Background technique

[0002] The hydrogen crushing of rare earth metal-based magnetic materials is to use the hydrogen absorption characteristics of alloy ingots and strips to make them embrittled, so as to effectively prepare coarse powder in a short time, and then heat the coarse powder to 400 in vacuum or inert atmosphere. At ~600°C, part of the absorbed hydrogen is released.

[0003] At present, the commonly used NdFeB rare earth permanent magnet alloy hydrogen crushing production equipment is the rotary furnace gall type hydrogen crushing furnace, which adopts water cooling, the cooling speed is low, and there are great safety hazards, and the energy consumption of the externally heated muffle furnace is also low. Very big. In addition, it is very difficult to take out the magnetic powder from this rotary furnace type hydrogen breaking furn...

Examples

Embodiment 1

[0024] The chemical composition of NdFeB magnets is: 31.9% Nd, 1.0% Dy, 1.0% Co, 0.10% Cu, 0.12% Ga, 0.3% Nb, 0.97% B, and the rest is Fe.

[0025] The following steps are taken to prepare rare earth permanent magnets.

[0026] (1) Melting

[0027] Raw materials are prepared in proportion, melted in a 600Kg / time strip casting furnace (strip casting), and cast into scales to finally obtain strips with an average thickness of 0.3 mm.

[0028] (2) Hydrogen fragmentation

[0029] (3) jet mill

[0030] Micropowder with an average particle size of 2-4 μm is produced in a jet mill with nitrogen as the working gas.

[0031] (4) Compression molding

[0032] In a nitrogen-protected closed press, the micropowder is pressed into a compact when the orientation field is 1.4T, and the mold adopts a conventional non-magnetic steel mold.

[0033] (5) Sintering

[0034] Stack the green compacts in any way, and sinter them in a vacuum sintering furnace at 1075°C for 4 hours.

[0035] (6) ...