CN104681268B - One kind improves the coercitive processing method of Sintered NdFeB magnet - Google Patents
One kind improves the coercitive processing method of Sintered NdFeB magnet Download PDFInfo
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- CN104681268B CN104681268B CN201310615389.6A CN201310615389A CN104681268B CN 104681268 B CN104681268 B CN 104681268B CN 201310615389 A CN201310615389 A CN 201310615389A CN 104681268 B CN104681268 B CN 104681268B
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Abstract
The invention belongs to Sintered NdFeB magnet preparation field, by the change to Sintered NdFeB magnet microstructure, to improve the coercivity of Sintered NdFeB magnet.The hydrogen comminuted powder that mixing step i.e. before the airflow milling powder of Sintered NdFeB magnet production adds a certain amount of metal Al powder or rare earth gallium alloy carries out airflow milling powder together with neodymium iron boron hydrogen comminuted powder, then it is molded by magnetic field orientating, isostatic pressed, sintering and tempering heat treatment prepare sintered NdFeB blank product, wherein, the rare earth gallium alloy is one or more combinations in praseodymium gallium alloy, neodymium gallium alloy, praseodymium neodymium gallium alloy, DyGa alloy and holmium gallium alloy, the Sintered NdFeB magnet coercivity prepared improves, but magnetic residual loss is smaller.
Description
Technical field
The invention belongs to sintered NdFeB (Nd-Fe-B) magnet preparation field, and in particular to one kind improves sintered NdFeB
The coercitive processing method of magnet.
Background technology
As the Nd-Fe-B permanent magnet material of third generation rare earth permanent-magnetic material, from nineteen eighty-three by SUMITOMO CHEMICAL metal and U.S. GM
Since company's commercialization first, the characteristics of due to high remanent magnetism, high-coercive force and high energy product, electric power electricity has been widely used in it
The fields such as son, communication, information, communications and transportation office automation, medicine equipment and military affairs.
Sintered NdFeB magnet is mainly by principal phase Nd2Fe14B, rich-Nd phase and boron-rich phase composition, rich-Nd phase are centered around principal phase
Nd2Fe14Around B phases, a small amount of boron-rich phase is distributed in some crystal boundaries and handed at corner.Wherein Nd2Fe14B phases, which are that magnetic is mutually main, to be determined
The microstructure of remanent magnetism and magnetic energy product, rich-Nd phase and magnet mainly determines the coercivity of magnet.The magnetic reversal machine of sintered NdFeB
Reason is reverse farmland Review On The Nucleation Mechanism, therefore the characteristic such as the magnetic phase boundray structure of magnet and composition has important work to the coercivity of magnet
With.
In the actual production of sintered neodymium iron boron material, neodymium is added in the form of praseodymium neodymium alloy, and iron is with the shape of pure iron
Formula is added, and boron is added in the form of ferro-boron, can also be according to the height of magnetic property in addition to adding these materials, during actual production
It is low, add other elements such as：The elements such as Dy, Tb, Ho, Gd, Y, Al, Nb, Zr, Ga, Cu, Co.Alloy melting in industry at present
Method be all to put into the material of these elements to be smelted into alloy in smelting furnace together, then by slab, hydrogen is broken, system
Powder, magnetic field orientating shaping, isostatic pressed, sintering and tempering heat treatment, the blank of sintered neodymium iron boron material is made.
Research shows that a small amount of Al is added in Sintered NdFeB magnet can significantly improve the coercivity of NdFeB material,
But a part of remanent magnetism can be reduced.Al is no atomic magnetic moment, and Al addition makes the coercitive raising of magnet, is because Al makes
Alloy grain refines, while rich-Nd phase and the lumpiness of rich B phases is diminished, and Al, which enters rich-Nd phase, improves rich-Nd phase and Nd2Fe14B
The infiltration angle of phase, makes rich-Nd phase be more uniformly distributed along crystal boundary.
A small amount of Ga is added in Sintered NdFeB magnet can effectively improve the intrinsic coercive of Sintered NdFeB magnet
Power, and remanent magnetism is hardly impacted.Ga and B is respectively provided with positive enthalpy of mixing, mutually exclusive with B, therefore is difficult to enter into
Nd2Fe14B phases, and Ga and Nd has very big negative heat of mixing, from binary phase diagraml, Ga forms low melting point chemical combination with Nd phase reactions
Thing.Therefore distributions of the Ga in Sintered NdFeB magnet is concentrated mainly on crystal boundary and crystal boundary is handed at corner, promotes the cause of liquid-phase sintering
Densification and raising rich-Nd phase are to Nd2Fe14The wetting action of B main phase grains, the microstructure for improving magnet is reacted with rich-Nd phase, more
Good playing is acted on the magnetic decoupling main phase grain, so as to improve the coercivity of magnet.The life of Sintered NdFeB magnet at present
In production, the addition of Al and Ga elements is all that the traditional alloying means used add metal Al or Ga directly i.e. in melting
Formed multicomponent alloy, such Al and Ga elements inevitably some enter principal phase, so raising it is coercitive simultaneously
The remanent magnetism of magnet, while losses of the metal Ga in melting inevitably can be also reduced, can also reduce the effect of coercivity raising
Fruit.Al, Ga element how is set rationally effectively to be distributed in the problem of magnet principal phase boundary is also very worth further investigation.
The content of the invention
In the production of current sintered neodymium iron boron material, coercitive method is improved based on addition metal Al and Ga
In, all it is Al and Ga is fused into together in alloy by alloyage process.The present invention is also based on adding Al and Ga to improve
Coercivity, but addition manner and method are completely different, using the batch mixing before the airflow milling powder produced in sintered NdFeB
Stage adds the hydrogen comminuted powder of certain metal Al powder or rare earth gallium alloy, and then powder processed, magnetic field orientating are molded, sinter and returned again
Sintered neodymium iron boron material is made in burning hot processing, to realize raising coercivity.
The purpose of the present invention is that the hydrogen comminuted powder of appropriate metal Al powder or rare earth gallium alloy is uniformly mixed into neodymium iron boron
In hydrogen comminuted powder, mixed neodymium iron boron hydrogen comminuted powder is then passed through into airflow milling powder, magnetic field orientating shaping, isostatic pressed, burning
Knot is prepared into sintered neodymium iron boron material with tempering heat treatment, realizes distribution of the Al or Ga elements in crystal boundary, improves the crystal boundary of magnet
Structure, so as to improve coercivity.The hydrogen comminuted powder of wherein rare earth gallium alloy be by rare earth gallium alloy by inhaling hydrogen, dehydrogenating technology after
To obtain.
The technical scheme is that：
(1) prepared by the hydrogen comminuted powder of the hydrogen comminuted powder of neodymium iron boron matrix and rare earth gallium alloy：
Proportionately it is divided into Rex1(Prx2Ndx3)xFe(100-x-y-z-x1-y1-y2-y3-y4-y5-y6)ByCozCuy1Nby2Zry3Aly4Gay5My6Meter
The weight of required various raw material is calculated, smelting furnace is added to together and alloy sheet, alloy is made by rapid hardening slab technique
Then between 0.2-0.4mm neodymium iron boron matrix is made by inhaling hydrogen-dehydrogenating technology in alloy sheet by the optimum thickness of thin slice
Hydrogen comminuted powder (wherein mass percent x:29.5-32.5；y:0.95-1.1；z:0-4；y1:0-0.3；y2:0-1；y3:0-0.3；
y4:0-2；y5:0-1；y6:0-1；x1:0-15；x2:0-25；x3:75-100；Re is one in Dy, Tb, Ho, Gd, La, Ce and Y
Kind or multiple combinations；M is one or more combinations in Si, Cr, Mo, Ti and W).By rare earth gallium alloy by inhaling hydrogen, dehydrogenation work
Skill is prepared into the hydrogen comminuted powder of rare earth gallium alloy, and rare earth gallium alloy can be praseodymium gallium alloy, neodymium gallium alloy, praseodymium neodymium gallium alloy, dysprosium
One or more combinations in gallium alloy, holmium gallium alloy.It can be carried out at normal temperature or 100-300 DEG C to inhale hydrogen, and desorption temperature is
500-580 DEG C, dehydrogenation time is 3-10 hours.
(2) it with the addition of the preparation of the Sintered NdFeB magnet of metal Al powder or rare earth gallium alloy hydrogen comminuted powder：By metal Al
Powder is added in the hydrogen comminuted powder of neodymium iron boron matrix in accordance with the appropriate ratio with obtained rare earth gallium alloy hydrogen comminuted powder, adds simultaneously
Enter appropriate antioxidant, the batch mixing 1-4 hours in batch mixer, the powder of granularity required for being then milled into by air-flow, then
It is molded by magnetic field orientating, isostatic pressed, vacuum-sintering and tempering heat treatment are prepared into the blank of sintered neodymium iron boron material.Metal Al
The addition of the hydrogen comminuted powder of powder and rare earth gallium alloy carries out appropriate selection according to performance requirement.The addition of antioxidant is
0.05%-0.2%.Powder size made of airflow milling requires：D50 (meso-position radius) is 3.5-5.8 μm, D (3,2) (surface area
Average grain diameter) it is 2.7-4 μm, maximum particle diameter is less than 16 μm, and D90/D10 is less than 6.Described magnetic field orientating shaping, is in magnetic field
Effect is lower to be suppressed simultaneously, and magnetic field intensity is more than 1.6T, and magnetic field intensity is the bigger the better.Vacuum-sintering, its sintering temperature are
1040-1080 DEG C, the sintered heat insulating time is 3-6 hours, and selection and the magnet composition of sintering temperature have bigger relation, sintered
The density of neodymium iron boron magnetic body is generally higher than 7.4g/m3.Described tempering heat treatment is two-stage, and one-level heat treatment temperature is 800-
950 DEG C, the time is 4-10 hours；Two level heat treatment temperature is 450-650 DEG C, and the time is 2-6 hours.
Embodiment
Below in conjunction with instantiation, the present invention is further detailed explanation.
Following instance is implemented premised on technical solution of the present invention, but protection scope of the present invention is not limited to down
The embodiment stated.
Implementation column 1
(1) composition (PrNd) is pressed31B more than Fe1Al0.3Cu0.1Co0.5The amount that various raw material need is calculated, then passes through speed
Solidifying slab technique is prepared into the alloy sheet that thickness is 0.2-0.4mm.
(2) alloy sheet is prepared into hydrogen comminuted powder by the broken technique of hydrogen, 0.2% metal Al is added in hydrogen comminuted powder
Powder, 0.1% antioxidant, then batch mixing 3 hours in batch mixer.
(3) powder after will be mixed is pressed into 51*51*27mm square by magnetic field orientating press, then enters one with isostatic pressed
Step compacting is closely knit, and alignment magnetic field pressure is 1.8T, hydrostatic pressure 150Mpa, dwell time 5s.
(4) the neodymium iron boron green compact after isostatic pressed are sintered into sintering furnace, sintering temperature is 1058 DEG C, and insulation 4 is small
When, during into sintered heat insulating, vacuum reaches 10-2 levels.Tempering heat treatment is divided into two stages, and first stage holding temperature is
900 DEG C, it is incubated 2.5 hours；Second stage holding temperature is 500 DEG C, and soaking time is 4 hours.After product is come out of the stove, in the product
Φ 10*10 cylinder is cut, for testing magnetic property.
The result of the embodiment 1 of table 1
Implementation column 2
(1) composition (PrNd) is pressed31B more than Fe1Al0.3Cu0.1Co0.5The amount that various raw material need is calculated, then passes through speed
Solidifying slab technique is prepared into the alloy sheet that thickness is 0.2-0.4mm.
(2) alloy sheet is prepared into hydrogen comminuted powder by the broken technique of hydrogen, 0.2% metal Al powder is added in hydrogen comminuted powder
With 0.15% neodymium gallium alloy, neodymium gallium alloy contains gallium 30%, 0.1% antioxidant, then batch mixing 3 hours in batch mixer.
(3) powder after will be mixed is pressed into 51*51*27mm square by magnetic field orientating press, then enters one with isostatic pressed
Step compacting is closely knit, and alignment magnetic field pressure is 1.8T, hydrostatic pressure 150Mpa, dwell time 5s.
(4) the neodymium iron boron green compact after isostatic pressed are sintered into sintering furnace, sintering temperature is 1058 DEG C, and insulation 4 is small
When, during into sintered heat insulating, vacuum reaches 10-2 levels.Tempering heat treatment is divided into two stages, and first stage holding temperature is
900 DEG C, it is incubated 2.5 hours；Second stage holding temperature is 500 DEG C, and soaking time is 4 hours.After product is come out of the stove, in the product
Φ 10*10 cylinder is cut, for testing magnetic property.
The result of the embodiment 2 of table 2
Claims (8)
- It is that the air-flow produced in Sintered NdFeB magnet is ground 1. one kind improves the coercitive processing method of Sintered NdFeB magnet Mixing step before powder, add a certain amount of metal Al powder and rare earth gallium alloy hydrogen comminuted powder and enter together with neodymium iron boron hydrogen comminuted powder Row airflow milling, then it is molded by magnetic field orientating, isostatic pressed, sintering and tempering heat treatment prepare the production of sintered NdFeB blank Product, wherein, the rare earth gallium alloy is one in praseodymium gallium alloy, neodymium gallium alloy, praseodymium neodymium gallium alloy, DyGa alloy and holmium gallium alloy Kind or multiple combinations.
- 2. the processing method described in claim 1, it is characterised in that concretely comprise the following steps：A) Nd Fe B alloys piece is made using rapid hardening slab technique first, it is then that Nd Fe B alloys piece hydrogen is broken；B) the hydrogen comminuted powder of a certain amount of metal Al powder and rare earth gallium alloy is added to the batch can equipped with neodymium iron boron hydrogen comminuted powder In, while add a certain amount of antioxidant；C) batch can is placed in operating 1-4 hours on mixer, mixed hydrogen flour material is then milled into powder by air-flow；D) manufactured powder is prepared into sintering neodymium iron by magnetic field orientating die mould, isostatic pressed, vacuum-sintering and tempering heat treatment Boron magnet blank product.
- 3. the processing method described in claim 1, it is characterised in that：The chemical formula of described neodymium iron boron magnetic body is：Rex1 (Prx2Ndx3)xFe(100-x-y-z-x1-y1-y2-y3-y4-y5-y6)ByCozCuy1Nby2Zry3Aly4Gay5My6, wherein mass percent x: 29.5-32.5；y:0.95-1.1；z:0-4；y1:0-0.3；y2:0-1；y3:0-0.3；y4:0-2；y5:0-1；y6:0-1；x1: 0-15；x2:0-25；x3:75-100；Re is one or more combinations in Dy, Tb, Ho, Gd, La, Ce and Y；M be Si, Cr, One or more combinations in Mo, Ti and W.
- 4. the processing method described in claim 2, it is characterised in that：The broken desorption temperature of described hydrogen is 500-580 DEG C, insulation Time is 3-10 hours.
- 5. the processing method described in claim 2, it is characterised in that：Described metal Al powder purities are more than 99%, and granularity is small In 300 mesh.
- 6. the processing method described in claim 2, it is characterised in that：The powder size of the airflow milling powder is：Meso-position radius D50 is 3.5-5.8 μm, and surface area average grain diameter D (3,2) is 2.7-4 μm, and maximum particle diameter is less than 16 μm, and D90/D10 is less than 6.
- 7. the processing method described in claim 2, it is characterised in that：Described vacuum-sintering, its sintering temperature are 1040- 1080 DEG C, the sintered heat insulating time is 3-6 hours.
- 8. the processing method described in claim 2, it is characterised in that：Described tempering heat treatment is two-stage, and one-level is heat-treated Temperature is 800-950 DEG C, and the time is 2-4 hours；Two level heat treatment temperature is 450-650 DEG C, and the time is 2-6 hours.
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| CN105206417B (en) * | 2015-11-09 | 2018-02-23 | 北京科技大学 | The preparation method of magnetic coupling sintered NdFeB is gone between a kind of main phase grain by force |
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| CN107464644A (en) * | 2017-09-06 | 2017-12-12 | 京磁材料科技股份有限公司 | The preparation method of performance Nd Fe B sintered magnet |
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| CN111403163B (en) * | 2020-01-07 | 2022-04-08 | 浙江凯文磁业有限公司 | Preparation method of high-corrosion-resistance sintered neodymium-iron-boron magnet |
| CN113421761B (en) * | 2021-06-12 | 2023-03-24 | 山西汇镪磁性材料制作有限公司 | Preparation method of high-performance sintered neodymium iron boron capable of reducing adsorption energy of modified magnetic powder |
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Effective date of registration: 20191010 Address after: 410000 Hunan province Changsha Furong district Zhanggongling Longping high tech Park Long Park Road No. 108 two Patentee after: Hunan Rare Earth New Engergy Material Co., Ltd. Address before: 410126 Hunan province Changsha Furong district Longping high tech Park Long Park Road No. 108 two Patentee before: Hunan Research Institute of Rare Earth Metal Materials |