CN103106993A - Ndfeb magnetic material with light rare earth element and preparation method thereof - Google Patents

Abstract

Disclosed are an ndfeb magnetic material with a light rare earth element and a preparation method thereof. The light rare earth element (La-Ce) is added according to a certain proportion into materials which are used for manufacturing rare earth permanent magnets, a using ratio of high-abundance rare earth materials is improved, and manufacturing cost of the rare earth permanent magnets is reduced. The light rare earth element is directly added into an ndfeb main phase with low rare earth content, appropriate adding can play a role of rich rare earth phases, and the situation that a product is oxidized due to the fact that the total quantity of the rare earth is too low is prevented. A strengthening effect on a grain boundary is achieved and coercivity is improved. Grains of ndfeb are restrained from growing in a sintering process, so that uniformity of size of grains inside the product is ensured, and rectangularity of the product is improved. Due to the fact that the element of the La-Ce is mainly gathered in the rich rare earth phases on the boundaries of the grains, the appropriate adding of the element of the La-Ce into the ndfeb materials can partially replace the neodymium (Nd) in a rich Nd phrase, consumption of the Nd is reduced, and therefore manufacturing cost of the product is greatly reduced.

Description

With neodymium-iron-boron magnetic material of light rare earth element and preparation method thereof

Technical field

The present invention relates to a kind of neodymium-iron-boron magnetic material technical field, specifically a kind of direct interpolation light rare earth element La-Ce preparation is cheaply with neodymium-iron-boron magnetic material of light rare earth element and preparation method thereof.

Background technology

Neodymium-iron-boron magnetic material is as the latest result of rare earth permanent-magnetic material development, because its excellent magnetic property is called as " magnetic king ".Neodymium-iron-boron magnetic material is the alloy of neodymium, boron, iron etc., claims again magnet steel.Neodymium iron boron has high magnetic energy product and coercive force, the advantage of high-energy-density is applied widely Nd-Fe-Bo permanent magnet material in modern industry and electronic technology simultaneously, thereby makes miniaturization, lightweight, the slimming of the equipment such as instrument and meter, electroacoustic motor, magnetic separation magnetization become possibility.

The reserves of China's rare earth resources account for 40% of world's gross reserves, in the manufacture process of neodymium iron boron, what mainly utilize is wherein to account for the neodymium of 15% left and right and the praseodymium of 8% left and right, and in praseodymium neodymium extractive process, the high abundance rare earth metal (as lanthanum, cerium etc.) in ore resource can only be processed as byproduct.Along with the increase year after year of Chinese neodymium iron boron output, rare earth resources is also correspondingly exploited in a large number as non-renewable resources, causes the high abundance rare earth resources such as lanthanum, cerium seriously to run off.

During although prepared rare-earth permanent magnet belongs to, low-grade permanent magnet, but because its cost hangs down and effectively utilized rare earth resources, thereby its in use, low-grade permanent magnet field industry will replace existing in, the application of low-grade neodymium iron boron magnetic body, occupy very large market.Estimate, along with the maturation of this product processes, in the near future, can with this Technique Popularizing in, all spectra of low-grade permanent magnet.Simultaneously, because this product price is lower, the extensive use that can be this product provides precondition.

Summary of the invention

The purpose of this invention is to provide a kind of neodymium-iron-boron magnetic material with light rare earth element and preparation method thereof.Main research and utilization adds light rare earth element (La-Ce) new technology of making rare-earth permanent magnet, improves the utilance of high abundance rare earth material, reduces the manufacturing cost of rare-earth permanent magnet.

The object of the present invention is achieved like this: the present invention is made of following a, b component, and described a component and percentage by weight form: (Pr-Nd_1-xGd_x) (x=0.13～0.26) be that 29～31%, B is that 1.0～1.1%, Al is that 0.5～1.0%, Cu is 0.05～0.4%, surplus is Fe; Described b component is La-Ce light rare earth additive, and this rare earth addition accounts for 0.1～5% of a component total amount.

Light rare earth additive of the present invention is that the standby particle diameter of employing HD-QLM legal system is the powder of 1.5～2.5 μ m.

The present invention passes through test of many times and proves, the rare earth addition that described b component is La-Ce accounts for 2.0～4.0% proportions for optimization of a component total amount.

The preparation method of the neodymium-iron-boron magnetic material with light rare earth element of the present invention is characterized in that:

1. first adopt SC-HD technique to prepare the neodymium iron boron principal phase, wherein a component is 3.0 * 10 in vacuum degree^-1Be smelted into the thin slice of thickness between 0.25～0.35mm under Pa, this thin slice normal temperature in the reactor of hydrogen crushing furnace is inhaled hydrogen and is heated to 550～650 ℃ of dehydrogenations 6～7 hours after 2～4 hours, and preparing granularity is that 60～80 purpose coarse granules are standby;

2. described coarse granule is milled to the fine powder that particle mean size is 2.5～3.5 μ m under 0.68～0.7 MPa operating pressure by QLM-400 type airflow milling; Then, in the argon shield atmosphere, adopt compound interpolation in jet-propelled normal direction fine powder to be referred to as the La-Ce light rare earth additive of b component, and evenly mixed 1～3 hour in batch mixer, and realize evenly being adsorbed in mixed-powder around the neodymium iron boron principal phase;

3. described mixed-powder is pressed into the green compact of 50～100 * 50～100 * 50～100mm specification in the orientation field of 2.0～2.5T, and these green compact make block finer and close through cold isostatic press again; Through the green compact of cold isostatic press by vacuum sintering furnace at 1050～1100 ℃ and 5.0 * 10^-3Sintering under Pa vacuum degree, wherein powder composition is reached each other and the neodymium iron boron principal phase between form Grain-Boundary Phase and become finished product.

Light rare earth of the present invention is that the standby particle diameter of employing HD-QLM legal system is the powder of 1.5～2.5 μ m.

Described SC-HD belongs to this professional skill field, and wherein, the strip rapid hardening method that Strip Casting technique (being called for short SC technique) is separated out by controlling primary crystal α-iron namely is with casting; HD(Hydrogen decrepition) technique is: the quick-fried broken technique of hydrogen; QLM technique is airflow milling technique.

The subjective role that the present invention adopts light rare earth to add modification is: form liquid phase in the time of 700～900 ℃ principal phase is wrapped up, play the effect that is coupled between principal phase of removing.

Essential element effect of the present invention:

The La-Ce element that adds mainly is enriched in the rich rare-earth phase of grain boundary, and crystal boundary is played invigoration effect, along with the increase of adding content, crystal boundary is further strengthened, and coercive force also improves thereupon, and remanent magnetism has a small amount of reduction, but when adding content over certain value, La-Ce begins to enter principal phase, La-Ce₂Fe₁₄The magnetocrystalline anisotropy of B and saturation magnetization are well below Nd₂Fe₁₄B, thus principal phase there is diluting effect, thus cause the sharply decline of whole magnet magnetic property.

The La-Ce element has played the effect of crystal grain thinning, the crystal grain that makes magnet that adds of light rare earth phase trends towards homogenizing and regularization, make bar shaped, quadrangle, wedge shape etc. contain sharp corners, the irregular crystal grain of the pole of figure and oversize or too small crystal grain greatly reduces even and disappears, make intergranule tightr, this process makes the squareness of magnet make moderate progress.In addition, La-Ce element majority has entered the rich rare-earth phase of crystal boundary, and part has replaced Nd.This can illustrate: add the La-Ce element in the NdFeB material and can partly replace the Nd of rich neodymium in mutually, reduce the consumption of Nd, reduce costs.

The present invention compared with prior art has following advantage:

1, the present invention adopts light rare earth element directly to add in the neodymium iron boron principal phase of low content of rare earth, and appropriate interpolation can be played the effect of rich rare-earth phase: prevent the too low and oxidation of product total amount of rare earth; Crystal boundary is played invigoration effect improve coercive force; Suppress the neodymium iron boron grain growth in sintering process, guarantee the uniformity of interiors of products grain size, thereby the squareness of product is made moderate progress.

2, because element La-Ce mainly is enriched in the rich rare-earth phase of grain boundary, the appropriate La-Ce element that adds in the NdFeB material can partly replace the Nd of rich neodymium in mutually, reduces the consumption of Nd, thereby greatly reduces the manufacturing cost of product.

The below will be described in further detail invention by example, but following example is only the present invention's example wherein, not represent the rights protection scope that the present invention limits, and the scope of the present invention is as the criterion with claims.

Embodiment

Embodiment 1:

The configuration main-phase alloy, the mass percent of raw material consists of: Pr-Nd:26.5%, Gd:4%, B:1.05%, Fe:67.45%, Al:0.8%, Cu:0.2% adopts SC-HD technique to prepare the neodymium iron boron principal phase: 3.0 * 10^-1Be smelted into the thin slice of thickness between 0.25～0.35mm under Pa vacuum degree, this thin slice normal temperature in the reactor of hydrogen crushing furnace is inhaled hydrogen and is heated to 600 ℃ of dehydrogenations 6.0 hours after 3.0 hours, and preparing granularity is that 60～80 purpose coarse granules are standby;

Adopting the standby particle diameter of HD-QLM legal system is the light rare earth La-Ce powder of 1.5～2.5 μ m.

Above-mentioned coarse granule is milled to by QLM-400 type airflow milling the fine powder that particle mean size is 2.5～3.5 μ m under the 0.68MPa operating pressure; Then, in the argon shield atmosphere, adopt jet-propelled method with light rare earth La-Ce powder in 2%, 3%, 4%(wt%) ratio is to add in the fine powder of 2.5～3.5 μ m to particle mean size, and evenly mixed 2 hours in batch mixer, make the La-Ce additive and evenly be adsorbed in neodymium iron boron principal phase mixed-powder on every side;

Above-mentioned mixed-powder is pressed into the green compact of 50 * 50 * 50mm specification in the orientation field of 2.0～2.5T, these green compact make block finer and close through cold isostatic press again; Through the green compact of cold isostatic press by vacuum sintering furnace at 1050～1100 ℃ and 5.0 * 10^-3Sintering under Pa vacuum degree, wherein nano components is reached each other and the neodymium iron boron principal phase between form Grain-Boundary Phase and get product.

As follows with the parameter of this embodiment related substances:

Product granularity is about 1～6 μ m, crystal grain distribution uniform and there is no obvious Phenomena of Grain Growth, and the space is less, so this product has magnetic property preferably.

Be accompanied by different La-Ce additions, the coercive force of Nd-Fe-Bo permanent magnet material is respectively 972kA/m, 994 kA/m, 997 kA/m, and remanent magnetism decreases.

Embodiment 2:

Be with embodiment 1 difference: the mass percent of raw material consists of: Pr-Nd:24.5%, and Gd:6%, B:1.05%, Fe:67.45%, Al:0.8%, Cu:0.2%, other process routes are with embodiment 1, and test data sees Table 1.

The material parameter relevant to this embodiment is similar to embodiment 1, slightly.

Embodiment 3:

Be with embodiment 1 difference: the mass percent of raw material consists of: Pr-Nd:22.5%, and Gd:8%, B:1.05%, Fe:67.45%, Al:0.8%, Cu:0.2%, other process routes are with embodiment 1, and test data sees Table 1.

The material parameter relevant to this embodiment is similar to embodiment 1, slightly.

Embodiment 1 to 3 test data is as shown in table 1:

Table 1 test data

Claims (6)

1. neodymium-iron-boron magnetic material with light rare earth element, it is made of following a, b component, and described a component and percentage by weight form: (Pr-Nd_1-xGd_x) (x=0.13～0.26) be that 29～31%, B is that 1.0～1.1%, Al is that 0.5～1.0%, Cu is 0.05～0.4%, surplus is Fe; Described b component is La-Ce light rare earth additive, and this rare earth addition accounts for 0.1～5% of A component total amount.

2. according to claim 1 with the neodymium-iron-boron magnetic material of light rare earth element, it is characterized in that: the light rare earth additive is that the standby particle diameter of employing HD-QLM legal system is the powder of 1.5～2.5 μ m.

3. according to claim 1 with the neodymium-iron-boron magnetic material of light rare earth element, it is characterized in that: described rare earth addition accounts for 2.0～4.0% of A component total amount.

4. preparation method with the neodymium-iron-boron magnetic material of light rare earth element is characterized in that:

1. first adopt SC-HD technique to prepare the neodymium iron boron principal phase, wherein a component is 3.0 * 10 in vacuum degree^-1Be smelted into the thin slice of thickness between 0.25-0.35mm under Pa, this thin slice normal temperature in the reactor of hydrogen crushing furnace is inhaled hydrogen and is heated to 550～650 ℃ of dehydrogenations 6～7 hours after 2～4 hours, and preparing granularity is that 60～80 purpose coarse granules are standby;

2. described coarse granule is milled to by QLM-400 type airflow milling the fine powder that particle mean size is 2.5～3.5 μ m under 0.68～0.7MPa operating pressure; Then, in the argon shield atmosphere, adopt compound interpolation in jet-propelled normal direction fine powder to be referred to as the La-Ce light rare earth additive of b component, and evenly mixed 1～3 hour in batch mixer, and realize evenly being adsorbed in mixed-powder around the neodymium iron boron principal phase;

3. described mixed-powder is pressed into the green compact of 50～100 * 50～100 * 50～100mm specification in the orientation field of 2.0～2.5T, and these green compact make block finer and close through cold isostatic press again; Through the green compact of cold isostatic press by vacuum sintering furnace at 1050～1100 ℃ and 5.0 * 10^-3Sintering under Pa vacuum degree, wherein powder composition is reached each other and the neodymium iron boron principal phase between form Grain-Boundary Phase and become finished product;

Described a component and percentage by weight form: (Pr-Nd_1-xGd_x) (x=0.13～0.26) be that 29～31%, B is that 1.0～1.1%, Al is that 0.5～1.0%, Cu is 0.05～0.4%, surplus is Fe; Described b component is La-Ce light rare earth additive, and this rare earth addition accounts for 0.1～5% of A component total amount.

5. the preparation method of neodymium-iron-boron magnetic material according to claim 4 is characterized in that: the light rare earth additive is that to adopt the standby particle diameter of HD-QLM legal system be the powder of 1.5～2.5 μ m.

6. the preparation method of neodymium-iron-boron magnetic material according to claim 4, it is characterized in that: described rare earth addition accounts for 2.0～4.0% of a component total amount.