CN105390225A - Corrosion-resistant NdFeB magnet and preparation method therefor - Google Patents

Corrosion-resistant NdFeB magnet and preparation method therefor Download PDF

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CN105390225A
CN105390225A CN201510835651.7A CN201510835651A CN105390225A CN 105390225 A CN105390225 A CN 105390225A CN 201510835651 A CN201510835651 A CN 201510835651A CN 105390225 A CN105390225 A CN 105390225A
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corrosion
resistant
magnet
preparation
magnetic body
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CN105390225B (en
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潘道良
苏广春
关井和
胡剑
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Ningbo Co-Star Materials Hi-Tech Co Ltd
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Ningbo Co-Star Materials Hi-Tech Co Ltd
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Abstract

The invention relates to an NdFeB magnet, in particular to a corrosion-resistant NdFeB magnet and a preparation method therefor, and belongs to the technical field of magnetic materials. The corrosion-resistant NdFeB magnet comprises the following components by mass: 26.00-30.00% of Nd, 1.00-2.50% of B, 0.80-1.50% of Si, 0.10-0.20% of Ga, 0.20-0.50% of Cu, 0.60-1.50% of Co, 0.10-0.30% of V, 0.20-0.60% of Dy and the balance of Fe. The preparation method comprises: performing material preparation, smelting, ingot casting, hydrogen decrepition, air-current milling, orientation and compression moulding to obtain an NdFeB magnet green body; pre-burning the green body at 500-600 DEG C for 2.0-3.0 hours, then heating to 1,180-1,220 DEG C at a speed of 15-22 DEG C/min, sintering for 0.5-2 hours, performing solution treatment at 1,150-1,180 DEG C for 2-3 hours, and quickly air-cooling to the room temperature to obtain a sintered blank; heating the sintered blank to 820-840 DEG C from the room temperature, keeping the temperature for 5-6 hours, slowly cooling to 520-600 DEG C at a cooling rate of 1-3 DEG C/min, and keeping the temperature for 2-4 hours; and finally, performing pre-plating and electroplating to obtain the finished NdFeB magnet. According to the NdFeB magnet, the corrosion resistance is greatly improved while coercive force, residual magnetism and magnetic energy product are increased.

Description

A kind of corrosion-resistant R-Fe-B magnet and preparation method thereof
Technical field
The present invention relates to a kind of neodymium iron boron magnetic body, be specifically related to a kind of corrosion-resistant R-Fe-B magnet and preparation method thereof, belong to technical field of magnetic materials.
Background technology
Neodymium iron boron magnetic body is the permanent magnetic material that in the world today, comprehensive magnetic can be the strongest, has the features such as high remanent magnetism, high-coercive force and high energy product.As rare earth permanent-magnetic material of new generation, neodymium iron boron magnetic body is all widely used in computer technology, auto industry, space flight military project, automatic technology, instrumental technique, microwave communication techniques, field of wind power generation.Neodymium iron boron magnetic body can be divided into Sintered NdFeB magnet and Agglutinate neodymium-iron-boron magnet, and wherein the magnetic property of Sintered NdFeB magnet is relatively better, is most widely used.But for sintered Nd-Fe-B permanent magnet, also there is the defects such as decay resistance is poor in it.
At present, in order to improve corrosion resistance, coercive force, the combination property such as remanent magnetism and magnetic energy product of Sintered NdFeB magnet, often add some auxiliary elements or by modes such as surface treatments.In the prior art, the auxiliary element of interpolation heavy rare earth Ho, Tb, Dy, Gd etc. often, but the resource of this kind of heavy rare earth is relatively less, and price comparison is expensive, adds multiple rare earth element, while improving magnet performance, also considerably increases production cost.Existing surface treatment generally has plating, chemical plating, electrophoresis, vacuum moulding machine and paint spraying etc.As Chinese invention patent application file (publication number: CN101440490A) discloses a kind of process for protecting of plating multilayer coating on surface of sintered Nd-Fe-B permanent magnet, concrete steps comprise Pre-treatment before plating, Electroless Plating Ni ZnP alloy and multilayer plating NiWP alloy (at least 3 layers).Although this technique can improve the decay resistance of neodymium iron boron magnetic body to a certain extent, its coating number is many, and technics comparing is complicated, and relative cost is also higher.
Summary of the invention
The object of the invention is for the deficiencies in the prior art, the neodymium iron boron magnetic body that a kind of corrosion resistance and good, coercive force are high is provided.
Object of the present invention realizes by following technical proposal: a kind of corrosion-resistant R-Fe-B magnet, its constituent and mass percent are: Nd:26.00%-30.00%, B:1.00%-2.50%, Si:0.80%-1.50%, Ga:0.10%-0.20%, Cu:0.20%-0.50%, Co:0.60%-1.50%, V:0.10%-0.30%, Dy:0.20%-0.60%, and surplus is Fe.
Neodymium iron boron magnetic body of the present invention is on the basis of Nd, Fe and B, with the addition of and can improve magnet anisotropy and coercitive Si and Ga, with the addition of the Cu that can increase magnet strength, coercive force and decay resistance, and partly can replace Fe and all can produce the Co acted synergistically to improve magnet performance with Cu and Dy, also added and partly can replace Nd and effectively improve the coercitive Dy of magnet and energy and the composite use of Dy greatly to improve the coercitive V of magnet.By the reasonable compatibility of each element and synergy in the present invention, effectively improve the comprehensive magnetic energy such as the coercive force of neodymium iron boron magnetic body.
Neodymium iron boron magnetic body of the present invention is on the basis of Nd, Fe and B, and the composite Si of adding and Ga can improve the coercive force, anisotropy etc. of magnet simultaneously, and can reduce the reduction of magnet remanent magnetism.And the composite corrosion resistance that can increase magnet on the one hand that adds of Cu and Co, then can form NdFeCoCu cenotype at grain boundaries on the other hand thus the intensity of raising magnet.Meanwhile, Cu can enter principal phase and improve the single shaft of NdFeB magnet respectively to different field property, and crystal grain thinning is to increase the specific area of crystal grain, makes rich neodymium Entropy density deviation more evenly thus greatly improves the coercive force of magnet.But can cause the generation of stress concentration phenomenon due to too much Cu content thus reduce the bending strength of magnet, therefore in neodymium iron boron magnetic body of the present invention, the content of Cu controls at 0.20%-0.50%.And Co partly can replace Fe and makes the Curie temperature of neodymium iron boron magnetic body raise thus effectively improve the residual magnetism temperature coefficient of neodymium iron boron magnetic body, be conducive to the magnetic property of enhancing magnet.But the precipitated phase that also can produce while Co part replaces Fe containing Co, cause magnet coercive force to decrease, therefore the present invention adds Cu to stop the generation of this phenomenon, controls the addition of Co at 0.60%-1.50% simultaneously.
Heavy rare earth element such as Dy, Gd, Tb etc. have high anisotropy field in NdFeB magnet, and have temperature compensation function, they add the NdFeB magnet that can obtain having high-coercive force and high-temperature stability.But the price of heavy rare earth also costly, considers production cost, in neodymium iron boron magnetic body of the present invention, only with the addition of rare earth element Dy.Dy is as one of the most effective element of coercive force improving permanent magnet, Dy partly can replace Nd on the one hand, significantly improve each to different field property of alloy, and the micro-structural improving magnet is effectively to improve the coercive force of magnet, Dy and Co, V, Cu all can produce synergy on the other hand, Dy, Co and Cu composite adds the decay resistance that not only can improve magnet and does not make its coercive force decline, effectively can also improve the structural constituent of the rich neodymium phase of crystal boundary, thus improve the resistance to Hydrogen Energy power of NdFeB magnet; And coercitive both the raisings added caused by caused coercitive raising and Dy of V are stackable with the coercive force greatly improving magnet, and V forms the V of disperse at grain boundaries 2feB 2to replace rich B phase wherein, raising magnet is coercitive while, therefore can not reduce again the remanent magnetism of magnet.
Neodymium iron boron magnetic body of the present invention is on the basis of Nd, Fe and B, compositely add Si, Ga, Cu, Co, V and Dy, by reasonable compatibility and the synergy of each element, obtain that there is higher coercive force, remanent magnetism and magnetic energy product, and the neodymium iron boron magnetic body of the good combination property such as corrosion resistance, intensity.
Further, as preferably, constituent and the mass percent of described corrosion-resistant R-Fe-B magnet are: Nd:27.00%-29.00%, B:1.50%-2.00%, Si:1.00%-1.30%, Ga:0.12%-0.18%, Cu:0.30%-0.40%, Co:0.80%-1.20%, V:0.15%-0.25%, Dy:0.30%-0.50%, and surplus is Fe.
Again further preferably, constituent and the mass percent of described corrosion-resistant R-Fe-B magnet are: Nd:28.00%, B:1.80%, Si:1.20%, Ga:0.15%, Cu:0.35%, Co:1.00%, V:0.20%, Dy:0.40%, and surplus is Fe.
The present invention also provides the method preparing above-mentioned corrosion-resistant R-Fe-B magnet, and described preparation method comprises the steps:
S1, batching and melting: prepare burden according to the constituent of above-mentioned corrosion-resistant R-Fe-B magnet and mass percent, will batching melting casting obtains the slab that thickness is 0.30-0.50mm;
S2, green compact are shaping: obtain after broken through hydrogen for above-mentioned slab, airflow milling the powder that average grain diameter is 3.0 μm-5.0 μm, then by powder in the protective atmosphere of nitrogen, under the pulsed magnetic field of 2.0T-3.0T orientation compressingly obtain neodymium iron boron magnetic body green compact;
S3, sintering solid solution, timeliness: by above-mentioned neodymium iron boron magnetic body green compact first pre-burning 2.0-3.0h at 500-600 DEG C, then 1180-1220 DEG C of sintering 0.5-2h is warming up to the speed of 15-20 DEG C/min, then in 1150 DEG C-1180 DEG C solid solution 2-3 hour, and fast wind is as cold as room temperature, obtain sintered blank, by sintered blank by room temperature to 820-840 DEG C of insulation timeliness 5-6 hour, subsequently with the cooldown rate slow cooling of 1-3 DEG C/min to 520 DEG C-600 DEG C, and be incubated 2-4 hour;
S4, surface treatment: the neodymium iron boron magnetic body blank after sintering solid solution, Ageing Treatment is obtained neodymium iron boron magnetic body finished product through preplating, electroplating processes.
For Sintered NdFeB magnet, the performance of control to neodymium iron boron magnetic body of sintering process plays a key effect.High temperature sintering (>1230 DEG C) is although slightly improve remanent magnetism and the coercive force of magnet, but the too high meeting of sintering temperature causes the abnormal grain growth in neodymium iron boron magnetic body, thus directly affect coercive force and the direction degree of the magnetic property of neodymium iron boron magnetic body, particularly magnet; And if sintering temperature is too low, then do not reach the object of neodymium iron boron magnetic body sintering.In order to obtain better sintering effect, in the preparation method of corrosion-resistant R-Fe-B magnet of the present invention before neodymium iron boron magnetic body green compact are carried out sintering prior to 500-600 DEG C at pre-burning 2.0-3.0h, and then be warming up to sintering temperature and sinter.
The present invention carries out solution treatment after sintering again at 1150 DEG C-1180 DEG C, effectively stop the abnormal growth of crystal grain in magnet further, make the rich neodymium Entropy density deviation of neodymium iron boron magnetic body more even, and can fully suppress magnet main phase grain by magneto-coupling effect etc., to obtain that there is the neodymium iron boron magnetic body compared with high magnetic characteristics.
Similarly, the Ageing Treatment after after the solution treatment of magnet sintering also has important impact to the magnetic property of final neodymium iron boron magnetic body.After neodymium iron boron magnetic body sinters, adopt secondary time effect process effectively to prevent magnet main phase grain border is not straight, Nd-rich phase in the generation of the phenomenons such as main phase grain border skewness, segregation are serious, ensure remanent magnetism and magnetic energy product change less while significantly improve the coercive force of neodymium iron boron magnetic body.And in order to obtain, there is the neodymium iron boron magnetic body compared with high magnetic characteristics, the temperature and time of conservative control secondary time effect.Along with the increase of aging temp and the prolongation of aging time, the magnetic properties such as the coercive force of magnet can be significantly improved, but too high aging temp and long aging time can cause the magnetic property of magnet to reduce on the contrary, therefore in the present invention all control the temperature in secondary time effect process and tempering time in above-mentioned suitable scope.
Neodymium iron boron magnetic body of the present invention also improves the magnetic property of magnet further by preplating, electroplating processes.
In the preparation method of above-mentioned corrosion-resistant R-Fe-B magnet, when preparing burden in step S1, raw material is added by following mode: Dy-Fe alloy, industrial ingot iron, electrolytic cobalt and cathode copper that the vanadium iron that the gallium ferroalloy that the ferrosilicon that the ferro-boron that the neodymium-iron alloy that Nd content is 65%-70%, B content are 20%-30%, Si content are 74%-80%, Ga content are 8%-10%, V content are 40%-50%, Dy content are 5%-8%.
In the preparation method of above-mentioned corrosion-resistant R-Fe-B magnet, the slab described in step S2 obtains the flour that average grain diameter is 9.0 μm-11.0 μm after the broken process of hydrogen.Compared with traditional Mechanical Crushing flouring technology, the present invention adopts the broken treatment process of hydrogen can not only reduce the ratio of transgranular fracture in pulverizing process, thus keep the integrality of crystal grain, and effectively can suppress the abnormal growth of crystal grain in sintering process, thus effectively improve the combination property of magnet.
In the preparation method of above-mentioned corrosion-resistant R-Fe-B magnet, the programming rate described in step S3 during Ageing Treatment is 10-30 DEG C/min.
For neodymium iron boron magnetic body of the present invention, in order to improve the corrosion resistance of magnet further, after obtaining neodymium iron boron magnetic body blank, electroplating processes is carried out to it.In the preparation method of above-mentioned corrosion-resistant R-Fe-B magnet, the Pre-treatment before plating described in step S4 comprises the conventional treatment before plating method such as oil removing, pickling, activation.After carrying out Pre-treatment before plating, in order to ensure that coating and matrix have good adhesion, in the preparation method of corrosion-resistant R-Fe-B magnet of the present invention, the mode of nickel preplating and electronickelling is adopted to electroplate neodymium iron boron magnetic body blank.
Wherein, in the preparation method of above-mentioned corrosion-resistant R-Fe-B magnet, described in step S4, the composition of the treatment fluid that pre-plating is used comprises: nickelous sulfate: 230-280g/L, inferior sodium phosphate: 15-35g/L, anhydrous sodium acetate: 10-15g/L, succinic acid: 0.01-0.1mol/L, polyethylene glycol: 0.03-0.1g/L, and solvent is water; During pre-plating, temperature is 45-55 DEG C, PH is 3.8-4.5, and the processing time is 30-50min, and coating average thickness is 3-8 μm.
The composition of the treatment fluid that described electroplating processes is used comprises: nickelous sulfate: 230-320g/L, nickel chloride: 40-80g/L, boric acid: 30-50g/L, para toluene sulfonamide: 0.05-0.1g/L, n-octyl sodium sulphate: 0.05-0.1g/L, natrium citricum: 5-12g/L, and solvent is water; During electroplating processes, temperature is 45-55 DEG C, PH is 4.0-4.6, and the processing time is 35-50min, and coating average thickness is 5-10 μm.
Compared with prior art, the present invention has following beneficial effect:
1) corrosion-resistant R-Fe-B magnet of the present invention, on the basis of Nd, Fe and B, compositely add Si, Ga, Cu, Co, V and rare earth β-diketone complex, by reasonable compatibility and the synergy of each element, the coercive force of the neodymium iron boron magnetic body obtained, remanent magnetism and magnetic energy product are all higher, and the good combination property such as corrosion resistance, intensity.
2) preparation method's simple possible of corrosion-resistant R-Fe-B magnet of the present invention, by the reasonable set of each technological parameter, especially by the combination property specifically sintering solid solution, Ageing Treatment and improve further neodymium iron boron magnetic body.
3), in the preparation method of corrosion-resistant R-Fe-B magnet of the present invention, obtained neodymium iron boron magnetic body blank is carried out electroplating processes, effectively raises the corrosion resistance of neodymium iron boron magnetic body further.
Embodiment
Be below specific embodiments of the invention, technical scheme of the present invention is further described, but the present invention is not limited to these embodiments.
Table 1: embodiment 1-5 is for the preparation of the constituent of corrosion-resistant R-Fe-B magnet and mass percent
Embodiment 1
Batching and melting: prepare burden according to the constituent of corrosion-resistant R-Fe-B magnet described in table 1 embodiment 1 and mass percent, will batching melting casting obtains the slab that thickness is 0.4mm;
Green compact are shaping: above-mentioned slab is broken that average grain diameter is the flour of 9.0 μm-11.0 μm through hydrogen, again flour is obtained through airflow milling the powder that average grain diameter is 3.0 μm-5.0 μm, then by powder in the protective atmosphere of nitrogen, under the pulsed magnetic field of 2.5T orientation compressingly obtain neodymium iron boron magnetic body green compact;
Sintering solid solution, timeliness: by above-mentioned neodymium iron boron magnetic body green compact first pre-burning 2.5h at 550 DEG C, be then warming up to 1200 DEG C of sintering 1h with the speed of 17 DEG C/min, then in 1160 DEG C of solid solutions 2.5 hours, and fast wind is as cold as room temperature, obtains sintered blank; With the programming rate of 20 DEG C/min by sintered blank by room temperature to 830 DEG C of insulation timeliness 5.5 hours, subsequently with the cooldown rate slow cooling of 2 DEG C/min to 560 DEG C, and be incubated 3 hours;
Surface treatment: the neodymium iron boron magnetic body blank after sintering solid solution, Ageing Treatment is obtained neodymium iron boron magnetic body finished product through preplating, electroplating processes.Wherein, the composition of the treatment fluid that pre-plating is used comprises: nickelous sulfate: 250g/L, inferior sodium phosphate: 25g/L, anhydrous sodium acetate: 12g/L, succinic acid: 0.06mol/L, polyethylene glycol: 0.06g/L, and solvent is water; During pre-plating, temperature is 50 DEG C, and PH is 4.2, and the time is 40min, and coating average thickness is 3-8 μm.The composition of the treatment fluid that electroplating processes is used comprises: nickelous sulfate: 280g/L, nickel chloride: 60g/L, boric acid: 40g/L, para toluene sulfonamide: 0.07g/L, n-octyl sodium sulphate: 0.08g/L, natrium citricum: 8g/L, and solvent is water; During electroplating processes, temperature is 50 DEG C, and PH is 4.2, and the time is 45min, and coating average thickness is 5-10 μm.
Embodiment 2
Batching and melting: prepare burden according to the constituent of corrosion-resistant R-Fe-B magnet described in table 1 embodiment 2 and mass percent, will batching melting casting obtains the slab that thickness is 0.35mm;
Green compact are shaping: above-mentioned slab is broken that average grain diameter is the flour of 9.0 μm-11.0 μm through hydrogen, again flour is obtained through airflow milling the powder that average grain diameter is 3.0 μm-5.0 μm, then by powder in the protective atmosphere of nitrogen, under the pulsed magnetic field of 2.2T orientation repressed shaping, isostatic pressed process obtains neodymium iron boron magnetic body green compact;
Sintering solid solution, timeliness: by above-mentioned neodymium iron boron magnetic body green compact first pre-burning 2.8h at 520 DEG C, be then warming up to 1190 DEG C of sintering 1.5h with the speed of 16 DEG C/min, then in 1170 DEG C of solid solutions 2 hours, and fast wind is as cold as room temperature, obtains sintered blank; With the programming rate of 15 DEG C/min by sintered blank by room temperature to 825 DEG C of insulation timeliness 6 hours, subsequently with the cooldown rate slow cooling of 2 DEG C/min to 540 DEG C, and be incubated 4 hours;
Surface treatment: the neodymium iron boron magnetic body blank after sintering solid solution, Ageing Treatment is obtained neodymium iron boron magnetic body finished product through preplating, electroplating processes.Wherein, the composition of the treatment fluid that pre-plating is used comprises: nickelous sulfate: 240g/L, inferior sodium phosphate: 30g/L, anhydrous sodium acetate: 11g/L, succinic acid: 0.08mol/L, polyethylene glycol: 0.05g/L, and solvent is water; During pre-plating, temperature is 48 DEG C, and PH is 4.0, and the time is 45min, and coating average thickness is 3-8 μm.The composition of the treatment fluid that electroplating processes is used comprises: nickelous sulfate: 260g/L, nickel chloride: 70g/L, boric acid: 35g/L, para toluene sulfonamide: 0.06g/L, n-octyl sodium sulphate: 0.08g/L, natrium citricum: 6g/L, and solvent is water; During electroplating processes, temperature is 48 DEG C, and PH is 4.2, and the time is 48min, and coating average thickness is 5-10 μm.
Embodiment 3
Batching and melting: prepare burden according to the constituent of corrosion-resistant R-Fe-B magnet described in table 1 embodiment 3 and mass percent, will batching melting casting obtains the slab that thickness is 0.45mm;
Green compact are shaping: above-mentioned slab is broken that average grain diameter is the flour of 9.0 μm-11.0 μm through hydrogen, again flour is obtained through airflow milling the powder that average grain diameter is 3.0 μm-5.0 μm, then by powder in the protective atmosphere of nitrogen, under the pulsed magnetic field of 2.8T orientation compressingly obtain neodymium iron boron magnetic body green compact;
Sintering solid solution, timeliness: by above-mentioned neodymium iron boron magnetic body green compact first pre-burning 2.2h at 580 DEG C, be then warming up to 1210 DEG C of sintering 0.8h with the speed of 18 DEG C/min, then in 1165 DEG C of solid solutions 3 hours, and fast wind is as cold as room temperature, obtains sintered blank; With the programming rate of 25 DEG C/min by sintered blank by room temperature to 835 DEG C of insulation timeliness 5 hours, subsequently with the cooldown rate slow cooling of 3 DEG C/min to 580 DEG C, and be incubated 2 hours;
Surface treatment: the neodymium iron boron magnetic body blank after sintering solid solution, Ageing Treatment is obtained neodymium iron boron magnetic body finished product through preplating, electroplating processes.Wherein, the composition of the treatment fluid that pre-plating is used comprises: nickelous sulfate: 270g/L, inferior sodium phosphate: 20g/L, anhydrous sodium acetate: 14g/L, succinic acid: 0.04mol/L, polyethylene glycol: 0.09g/L, and solvent is water; During pre-plating, temperature is 52 DEG C, and PH is 4.3, and the time is 35min, and coating average thickness is 3-8 μm.The composition of the treatment fluid that electroplating processes is used comprises: nickelous sulfate: 300g/L, nickel chloride: 50g/L, boric acid: 45g/L, para toluene sulfonamide: 0.08g/L, n-octyl sodium sulphate: 0.06g/L, natrium citricum: 10g/L, and solvent is water; During electroplating processes, temperature is 52 DEG C, and PH is 4.5, and the time is 38min, and coating average thickness is 5-10 μm.
Embodiment 4
Batching and melting: prepare burden according to the constituent of corrosion-resistant R-Fe-B magnet described in table 1 embodiment 4 and mass percent, will batching melting casting obtains the slab that thickness is 0.50mm;
Green compact are shaping: above-mentioned slab is broken that average grain diameter is the flour of 9.0 μm-11.0 μm through hydrogen, again flour is obtained through airflow milling the powder that average grain diameter is 3.0 μm-5.0 μm, then by powder in the protective atmosphere of nitrogen, under the pulsed magnetic field of 2.0T orientation repressed shaping, isostatic pressed process obtains neodymium iron boron magnetic body green compact;
Sintering solid solution, timeliness: by above-mentioned neodymium iron boron magnetic body green compact first pre-burning 3.0h at 500 DEG C, be then warming up to 1180 DEG C of sintering 2h with the speed of 15 DEG C/min, then in 1150 DEG C of solid solutions 3 hours, and fast wind is as cold as room temperature, obtains sintered blank; With the programming rate of 10 DEG C/min by sintered blank by room temperature to 840 DEG C of insulation timeliness 6 hours, subsequently with the cooldown rate slow cooling of 1 DEG C/min to 520 DEG C, and be incubated 4 hours;
Surface treatment: the neodymium iron boron magnetic body blank after sintering solid solution, Ageing Treatment is obtained neodymium iron boron magnetic body finished product through preplating, electroplating processes.Wherein, the composition of the treatment fluid that pre-plating is used comprises: nickelous sulfate: 280g/L, inferior sodium phosphate: 15g/L, anhydrous sodium acetate: 15g/L, succinic acid: 0.01mol/L, polyethylene glycol: 0.1g/L, and solvent is water; During pre-plating, temperature is 45 DEG C, and PH is 4.5, and the time is 30min, and coating average thickness is 8 μm.The composition of the treatment fluid that electroplating processes is used comprises: nickelous sulfate: 230g/L, nickel chloride: 80g/L, boric acid: 30g/L, para toluene sulfonamide: 0.1g/L, n-octyl sodium sulphate: 0.05g/L, natrium citricum: 12g/L, and solvent is water; During electroplating processes, temperature is 45 DEG C, and PH is 4.6, and the time is 35min, and coating average thickness is 10 μm.
Embodiment 5
Batching and melting: prepare burden according to the constituent of corrosion-resistant R-Fe-B magnet described in table 1 embodiment 5 and mass percent, will batching melting casting obtains the slab that thickness is 0.30mm;
Green compact are shaping: above-mentioned slab is broken that average grain diameter is the flour of 9.0 μm-11.0 μm through hydrogen, again flour is obtained through airflow milling the powder that average grain diameter is 3.0 μm-5.0 μm, then by powder in the protective atmosphere of nitrogen, under the pulsed magnetic field of 3.0T orientation compressingly obtain neodymium iron boron magnetic body green compact;
Sintering solid solution, timeliness: by above-mentioned neodymium iron boron magnetic body green compact first pre-burning 2.0h at 600 DEG C, be then warming up to 1220 DEG C of sintering 0.5h with the speed of 20 DEG C/min, then in 1180 DEG C of solid solutions 2 hours, and fast wind is as cold as room temperature, obtains sintered blank; With the programming rate of 30 DEG C/min by sintered blank by room temperature to 820 DEG C of insulation timeliness 5 hours, subsequently with the cooldown rate slow cooling of 3 DEG C/min to 600 DEG C, and be incubated 2 hours;
Surface treatment: the neodymium iron boron magnetic body blank after sintering solid solution, Ageing Treatment is obtained neodymium iron boron magnetic body finished product through preplating, electroplating processes.Wherein, the composition of the treatment fluid that pre-plating is used comprises: nickelous sulfate: 230g/L, inferior sodium phosphate: 35g/L, anhydrous sodium acetate: 10g/L, succinic acid: 0.1mol/L, polyethylene glycol: 0.03g/L, and solvent is water; During pre-plating, temperature is 55 DEG C, and PH is 3.8, and the time is 50min, and coating average thickness is 3 μm.The composition of the treatment fluid that electroplating processes is used comprises: nickelous sulfate: 320g/L, nickel chloride: 40g/L, boric acid: 50g/L, para toluene sulfonamide: 0.05g/L, n-octyl sodium sulphate: 0.1g/L, natrium citricum: 5g/L, and solvent is water; During electroplating processes, temperature is 55 DEG C, and PH is 4.0, and the time is 50min, and coating average thickness is 5 μm.
During batching, raw material is added by following mode in the above-described embodiments: Dy-Fe alloy, industrial ingot iron, electrolytic cobalt and cathode copper that the vanadium iron that the gallium ferroalloy that the ferrosilicon that the ferro-boron that the neodymium-iron alloy that Nd content is 65%-70%, B content are 20%-30%, Si content are 74%-80%, Ga content are 8%-10%, V content are 40%-50%, Dy content are 5%-8%.
Comparative example
Neodymium iron boron magnetic body common in prior art.
Neodymium iron boron magnetic body in embodiment 1-5 and comparative example is carried out performance test, and result is as shown in table 2.
Neodymium iron boron magnetic body the performance test results in table 2: embodiment of the present invention 1-5 and comparative example
Neodymium iron boron magnetic body in embodiment 1-5 is carried out the decay resistance test of neutral salt spray test, and with adopt the raw material identical with embodiment 1-5 and preparation method to prepare but the decay resistance not carrying out the neodymium iron boron magnetic body electroplated compares, result is as shown in table 3.
Neodymium iron boron magnetic body decay resistance test result in table 3: embodiment of the present invention 1-5 and comparative example 1-5
In the process that wherein decay resistance is tested, the specification of the neodymium iron boron magnetic body of embodiment and comparative example is D10*3.
In sum, corrosion-resistant R-Fe-B magnet of the present invention adopts rational chemical composition, by the synergy between each composition and reasonable compatibility, the coercive force of the neodymium iron boron magnetic body obtained, remanent magnetism and magnetic energy product are all higher, and the decay resistance of neodymium iron boron magnetic body after electroplating processes significantly improves.
Specific embodiment described herein is only to the explanation for example of the present invention's spirit.Those skilled in the art can make various amendment or supplement or adopt similar mode to substitute to described specific embodiment, but can't depart from spirit of the present invention or surmount the scope that appended claims defines.

Claims (10)

1. a corrosion-resistant R-Fe-B magnet, it is characterized in that, constituent and the mass percent of described corrosion-resistant R-Fe-B magnet are: Nd:26.00%-30.00%, B:1.00%-2.50%, Si:0.80%-1.50%, Ga:0.10%-0.20%, Cu:0.20%-0.50%, Co:0.60%-1.50%, V:0.10%-0.30%, Dy:0.20%-0.60%, and surplus is Fe.
2. a kind of corrosion-resistant R-Fe-B magnet according to claim 1, it is characterized in that, constituent and the mass percent of described corrosion-resistant R-Fe-B magnet are: Nd:27.00%-29.00%, B:1.50%-2.00%, Si:1.00%-1.30%, Ga:0.12%-0.18%, Cu:0.30%-0.40%, Co:0.80%-1.20%, V:0.15%-0.25%, Dy:0.30%-0.50%, and surplus is Fe.
3. a kind of corrosion-resistant R-Fe-B magnet according to claim 1 and 2, it is characterized in that, constituent and the mass percent of described corrosion-resistant R-Fe-B magnet are: Nd:28.00%, B:1.80%, Si:1.20%, Ga:0.15%, Cu:0.35%, Co:1.00%, V:0.20%, Dy:0.40%, and surplus is Fe.
4. a preparation method for corrosion-resistant R-Fe-B magnet, is characterized in that, described preparation method comprises the steps:
S1, batching and melting: prepare burden according to the constituent of described corrosion-resistant R-Fe-B magnet and mass percent, will batching melting casting obtains the slab that thickness is 0.30-0.50mm;
S2, green compact are shaping: obtain after broken through hydrogen for above-mentioned slab, airflow milling the powder that average grain diameter is 3.0 μm-5.0 μm, then by powder in the protective atmosphere of nitrogen, under the pulsed magnetic field of 2.0T-3.0T orientation compressingly obtain neodymium iron boron magnetic body green compact;
S3, sintering solid solution, timeliness: by above-mentioned neodymium iron boron magnetic body green compact first pre-burning 2.0-3.0h at 500-600 DEG C, then 1180-1220 DEG C of sintering 0.5-2h is warming up to the speed of 15-20 DEG C/min, then in 1150 DEG C-1180 DEG C solid solution 2-3 hour, and fast wind is as cold as room temperature, obtains sintered blank; Again by sintered blank by room temperature to 820-840 DEG C of insulation timeliness 5-6 hour, subsequently with the cooldown rate slow cooling of 1-3 DEG C/min to 520 DEG C-600 DEG C, and be incubated 2-4 hour;
S4, surface treatment: the neodymium iron boron magnetic body blank after sintering solid solution, Ageing Treatment is obtained neodymium iron boron magnetic body finished product through preplating, electroplating processes.
5. the preparation method of corrosion-resistant R-Fe-B magnet according to claim 4, it is characterized in that, in step S2, slab obtains the flour that average grain diameter is 9.0 μm-11.0 μm after the broken process of hydrogen.
6. the preparation method of corrosion-resistant R-Fe-B magnet according to claim 4, it is characterized in that, the programming rate described in step S3 during Ageing Treatment is 10-30 DEG C/min.
7. the preparation method of corrosion-resistant R-Fe-B magnet according to claim 4, it is characterized in that, in step S4, the composition of the treatment fluid that pre-plating is used comprises: nickelous sulfate: 230-280g/L, inferior sodium phosphate: 15-35g/L, anhydrous sodium acetate: 10-15g/L, succinic acid: 0.01-0.1mol/L, polyethylene glycol: 0.03-0.1g/L, and solvent is water.
8. the preparation method of corrosion-resistant R-Fe-B magnet according to claim 4 or 7, it is characterized in that, during pre-plating, temperature is 45-55 DEG C, PH is 3.8-4.5, and the processing time is 30-50min, and coating average thickness is 3-8 μm.
9. the preparation method of corrosion-resistant R-Fe-B magnet according to claim 4, it is characterized in that, in step S4, the composition of the treatment fluid that electroplating processes is used comprises: nickelous sulfate: 230-320g/L, nickel chloride: 40-80g/L, boric acid: 30-50g/L, para toluene sulfonamide: 0.05-0.1g/L, n-octyl sodium sulphate: 0.05-0.1g/L, natrium citricum: 5-12g/L, and solvent is water.
10. the preparation method of corrosion-resistant R-Fe-B magnet according to claim 4 or 9, it is characterized in that, during electroplating processes, temperature is 45-55 DEG C, PH is 4.0-4.6, and the processing time is 35-50min, and coating average thickness is 5-10 μm.
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CN108417375A (en) * 2018-02-05 2018-08-17 宁波松科磁材有限公司 A kind of preparation method without heavy rare earth sintered Nd-Fe-B permanent magnet
CN109637769A (en) * 2019-01-26 2019-04-16 郑州工业应用技术学院 A kind of magnetism performance and the magnetic material of corrosion resistance and good and preparation method thereof
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CN111435617A (en) * 2019-01-15 2020-07-21 绵阳市恒信磁性材料有限公司 Preparation method of rare earth permanent magnetic material
CN112216462A (en) * 2020-09-26 2021-01-12 宁波合力磁材技术有限公司 Cerium-containing neodymium-iron-boron magnet with good corrosion resistance and preparation method thereof
CN112768169A (en) * 2020-12-30 2021-05-07 包头天和磁材科技股份有限公司 Preform, method for producing the same, method for producing corrosion-resistant magnet, and use of the same
CN113470961A (en) * 2021-07-15 2021-10-01 马桂英 Neodymium iron boron material and preparation process thereof
CN114566370A (en) * 2022-03-02 2022-05-31 浙江大学 Method for improving corrosion resistance of neodymium iron boron by low-temperature oxidation/nitridation treatment

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CN102237166A (en) * 2010-04-29 2011-11-09 比亚迪股份有限公司 Neodymium iron boron permanent magnet material and preparation method thereof

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CN101728042A (en) * 2008-10-16 2010-06-09 北京中科三环高技术股份有限公司 Technique for treating surface of permanent magnet material
CN102039630A (en) * 2009-10-14 2011-05-04 三环瓦克华(北京)磁性器件有限公司 Compression moulding method for annular rare-earth magnet
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CN108417375A (en) * 2018-02-05 2018-08-17 宁波松科磁材有限公司 A kind of preparation method without heavy rare earth sintered Nd-Fe-B permanent magnet
CN111435617A (en) * 2019-01-15 2020-07-21 绵阳市恒信磁性材料有限公司 Preparation method of rare earth permanent magnetic material
CN109637769A (en) * 2019-01-26 2019-04-16 郑州工业应用技术学院 A kind of magnetism performance and the magnetic material of corrosion resistance and good and preparation method thereof
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CN112216462A (en) * 2020-09-26 2021-01-12 宁波合力磁材技术有限公司 Cerium-containing neodymium-iron-boron magnet with good corrosion resistance and preparation method thereof
CN112216462B (en) * 2020-09-26 2024-05-28 宁波合力磁材技术有限公司 Cerium-containing neodymium-iron-boron magnet with good corrosion resistance and preparation method thereof
CN112768169A (en) * 2020-12-30 2021-05-07 包头天和磁材科技股份有限公司 Preform, method for producing the same, method for producing corrosion-resistant magnet, and use of the same
CN113470961A (en) * 2021-07-15 2021-10-01 马桂英 Neodymium iron boron material and preparation process thereof
CN114566370A (en) * 2022-03-02 2022-05-31 浙江大学 Method for improving corrosion resistance of neodymium iron boron by low-temperature oxidation/nitridation treatment

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