CN101615463A - A kind of highly corrosion resistant R-Fe-B magnet and preparation method thereof - Google Patents
A kind of highly corrosion resistant R-Fe-B magnet and preparation method thereof Download PDFInfo
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- CN101615463A CN101615463A CN200910116871A CN200910116871A CN101615463A CN 101615463 A CN101615463 A CN 101615463A CN 200910116871 A CN200910116871 A CN 200910116871A CN 200910116871 A CN200910116871 A CN 200910116871A CN 101615463 A CN101615463 A CN 101615463A
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Abstract
The present invention relates to a kind of highly corrosion resistant R-Fe-B magnet and preparation method thereof, be coated with thickness more than or equal to 2um and be penetrated into easy fusing and the corrosion-resistant non-magnetic metal alloy of its internal depth more than or equal to 2um at the magnet body surface.The preparation method comprises the melting steel ingot; Steel ingot is broken into particle; Be broken into powder again; Die mould becomes cylindrical magnet; Make alloying metal fusing and fully stirring with 550 ℃ ambient temperatures; Again cylindrical magnet being put into molten metal alloy solution during sintering allows metal alloy solution permeate 3 hours; The taking-up magnet is put into and is with the airtight cooler bin gas of inert gas air-cooled to quench from metal alloy solution, and natural cooling; At the vacuum sintering furnace sintering; Cylindrical grinding and section.Magnet antiseptic power of the present invention is strong, has significantly reduced because of there is the corrosion of residual liquid to magnet at pore, pinprick place, process of surface treatment does not have the plating situation to pore and pinprick place hidden danger such as also avoids electroplating to greatest extent.
Description
Technical field
The present invention relates to rare earth permanent-magnetic material of a kind of highly corrosion resistant and preparation method thereof.
Background technology
The highly corrosion resistant rare earth permanent-magnetic material can make magnet enter under the extreme environment and use, and even just can directly not use with electroplating surface.In the last few years, progressively enter applications such as wind-driven generator, specific type of electric machine, electric motor of automobile along with rare earth permanent-magnetic material, its requirement to highly corrosion resistant also constantly increases.Because of the borderline phase of sintering R-Fe-B series magnet is active rich rare earth phase, with principal phase (R
2Fe
14B) electronegativity of phase is on the low side too many, so the corrosion of magnet all from borderline phase, and just can produce H in case corrosion reaction takes place
2, and aggravation destroys magnet, makes magnet become powder, and then causes coating to bubble or come off.
In the prior art, process of surface treatment such as plating, electrophoresis are the anti-corrosion measure of rare earth magnet as R-Fe-B and are adopted in a large number, but there are a lot of pores in the R-Fe-B rare earth magnet surface that powder metallurgy sintered method is made, plating, electrophoresis or chemical plating method can only reach common anticorrosion reliability test requirements document, for example the salt mist test of nickel plating-copper-nickel product generally only guarantee 100 hours with interior coating non-corrosive and foaming, PCT generally only guarantees 48 hours with interior coating non-corrosive and foaming.And in pickling, cleaning and electroplating process, meeting residual fraction acid solution, power and water plating bath etc. in magnet surface pore or corrosion layer, these residuals can continue after electroplating technology is finished and magnet generation chemical reaction, thereby make R-Fe-B matrix formation powder with the coating junction, coating the reduction binding force of cladding material occurs separating with matrix, severe patient coating can occur and come off and block the motor rotating part, greatly influences the use or the life-span of motor.At these situations, all adopt metals such as adding Cu, Co, Ca to improve rare earth magnet structure and composition at present, the electronegativity of borderline phase material and the electronegativity difference of principal phase are reduced, reduce the speed that primary cell reaction takes place for it, adopt phosphorus sheet alloy thin band technology simultaneously,, improve density to reduce its grain size, reduce porosity etc., reduce the possibility of matrix corrosion.But thoroughly do not solve the anticorrosion defective of magnet, this enters electromechanics trade for sintering R-Fe-B based permanent magnet, and especially the high-end large-scale machine field still exists bigger difficulty and risk.
Summary of the invention
The present invention is directed to the deficiencies in the prior art, provide a kind of antiseptic power strong, significantly reduced because of there is the corrosion of residual liquid to magnet at pore, pinprick place, process of surface treatment such as also avoiding electroplating does not to greatest extent have highly corrosion resistant R-Fe-B magnet of plating situation hidden danger and preparation method thereof to pore and pinprick place.
The present invention is achieved by the following technical solutions:
A kind of highly corrosion resistant R-Fe-B magnet comprises R-Fe-B series magnet body, is coated with thickness more than or equal to 2um and be penetrated into easy fusing and the corrosion-resistant non-magnetic metal alloy of its internal depth more than or equal to 2um at described magnet body surface; Described metal alloy is one or more of Zn, Al, Cu, Ag, Ga, Cr, Sb, Sn, Zr, Ti, Pb, Bi, In, Cd, Ca.
A kind of highly corrosion resistant R-Fe-B magnet, described metal alloy are penetrated into and replace rich rare earth phase and boron-rich phase in the described magnet body top layer, and metal alloy spreads or permeate the new alloy-layer of formation mutually mutually with rich rare earth with rich B simultaneously.
The concentration that a kind of highly corrosion resistant R-Fe-B magnet, described metal alloy are penetrated in the described magnet body top layer along with the increase metal alloy of the degree of depth reduces gradually.
A kind of preparation method of highly corrosion resistant R-Fe-B magnet is according to the formulation ratio raw material and be smelted into steel ingot in vacuum melting furnace; Again with steel ingot with in be broken into particle in the broken machine; Be broken into powder with the airflow milling micro mist; Die mould becomes cylindrical magnet; At the vacuum sintering furnace sintering; Cylindrical grinding and section; All magnets are made chamfering, the pickling pre-treatment, and this method ambient temperature with 450 ℃～650 ℃ before the vacuum sintering furnace sintering makes described alloying metal fusing and fully stirring; The cylindrical magnet that more described die mould is become during sintering is put into molten metal alloy solution allows metal alloy solution permeate 0.5～10 hour; The treated magnet of taking-up is put into and is with the airtight cooler bin gas of inert gas air-cooled to quench from metal alloy solution, and natural cooling.
A kind of preparation method of highly corrosion resistant R-Fe-B magnet after described pickling pre-treatment, makes electroplating processes with magnet.
A kind of preparation method of highly corrosion resistant R-Fe-B magnet, described magnet put into molten metal alloy solution in addition the liquation of 0～200mpa pressure handled 0.5～10 hour.
The present invention utilizes a kind of easy fusing and corrosion-resistant non-magnetic metal alloy, this metal alloy is more than magnet surface covers 2um and be penetrated into and replace rich rare earth in the top layer more than the inner 2um mutually and boron-rich phase, metal alloy spreads or permeates the new alloy-layer of formation mutually mutually with rich rare earth with rich B simultaneously, and along with the concentration of the increase metal alloy of the degree of depth reduces, it the rich rare earth of nexine mutually and boron-rich phase and the external world separate, because of metal alloy is that the very stable high corrosion-resistant of chemical can be used for doing electrodeposited coating material element composition, improved the antiseptic power of magnet greatly; The diffusion of while metal alloy and pore, the pinprick that magnet surface is filled up in infiltration, this has significantly reduced because of there is the corrosion of residual liquid to magnet at pore, pinprick place, process of surface treatment does not have the plating situation to pore and pinprick place hidden danger such as also avoids electroplating to greatest extent.Secondly, any magnet after processed, no matter be through processing such as section, mill processing, line cutting, Vertical Mills, damage is brought to the crystal grain of magnet surface to be machined in the capital, part crystal grain becomes flexible itself and matrix generation owing to inevitably vibrating when processing is divided into two, and this has significantly influenced the adhesion of coating.In addition the magnet part surface in the course of processing because the corrosion of cooling fluid and electric spark, make the corrosion depth of rich rare earth phase reach more than 10～200um, only stay principal phase becomes mutually with the small part rare earth and is similar to loosening " coral reef " zone in this zone, and can bring greatly may of residual acid solution and plating bath space, after electroplating, this zone can form galvanic corrosion and coating is come off with prestissimo, influences the adhesion of coating etc.Because the diffusion of metal alloy is entered, reinforced and be divided into two and loosening crystal grain, metal alloy has been filled up because of processing causes the zone of corroding simultaneously, have destruction acid solution, plating bath etc. squeeze and cement out, crystal grain has been produced reinforcement effect.Metal alloy is non-magnetic metal in addition, enter the rich rare earth in border and can improve the pinning effect ability in the magnetic domain forming core district that gets along on principal phase and border after mutually, remedy and improved the coercive force of the place's of being corroded reduction, thereby improve for example whole magnetic property of performance such as magnetic flux, table magnetic of magnet.Especially at magnet thickness during, improve just obvious more and thin more its effect of magnet is outstanding more less than 2mm.
The magnet that according to said method produces can not need surface treatment just can reach 200 hours non-corrosives of salt mist test and the remarkable result of PCT test more than 100 hours, thereby reach the fields such as directly to be applied in motor of to electroplate, as continue to do the surface and handle coating, can improve 10～20 times antiseptic power and electroplate adhesion.Magnet needn't be done second level timeliness after finishing 900 ℃ of level timeliness through sintering is intact in the inventive method; because the metal alloy temperature ranges also is the second level aging temp of magnet; promptly also allow simultaneously the magnet be to have made Ageing Treatment in heat conduction and the protective medium at the metal alloy liquation at surface-treated; if add and be band magnetic processing technology man-hour; magnet inevitably can be with magnetic and influence electroplating quality; must do demagnetization before electroplating and handle, the present invention also can allow magnet be issued to the demagnetization treatment effect in the protection of metal alloy liquation.This has significantly reduced the energy waste of doing timeliness and demagnetization treatment process in addition, make the efficient height of timeliness and demagnetization than vacuum sintering furnace, only need to get final product more than 1 hour, and the metal alloy liquation medium that has been heated to high temperature do not need just can continue to put into production use with magnet cooling, reduced in order to sintering furnace and done the intensification of timeliness and demagnetization, the time of cooling.
Its test result of magnet that different modes is handled is as follows:
Table 1: after the pickling of commonsense method magnet and through pickling remake the present invention handle after the table magnetic of magnet and weightless test (weight that 120 °, 0.2 metal pa, 100%RH damp condition lose after its magnet efflorescence of test down):
| Average center table magnetic | 48H is on average weightless | 144H is on average weightless | 500H is on average weightless | |
| The commonsense method magnet | ??1221Gs | ?43mg/cm2 | All efflorescence | ??--- |
| The present invention handles magnet | ??1361Gs | ?0mg/cm2 | ??0mg/cm2 | ??0.2mg/cm2 |
Hence one can see that compares with undressed magnet through the magnet of the present invention's processing, average center table magnetic goes up more than 10%, whole oxidations powdered after undressed magnet reached 144 hours, substantially there is not weightlessness and reach 144 hours through the magnet that metal alloy is handled, the weightlessness that 0.2-0.3mg/cm2 is just arranged when reaching 500 hours has embodied the magnet handled through this programme in magnetic property and the matrix advantage aspect anticorrosion.
Table 2: the different surface treatment mode is respectively got 20 and is made salt mist test (35 ° with 5% NaCl solution spraying), and it is as follows to calculate average result:
| 72 hours | 96 hours | 144 hours | 288 hours | 500 hours | 1000 hours | |
| The present invention handles magnet and does not electroplate | Non-corrosive | Non-corrosive | Non-corrosive | Get rusty 6 | Get rusty 17 | Get rusty 20 |
| The commonsense method magnet is electroplated NI-CU-NI | Non-corrosive | Get rusty 3 | Get rusty 20 | ?--- | ?--- | ??--- |
| The present invention handles magnet re-plating NI-CU-NI | Non-corrosive | Non-corrosive | Non-corrosive | Non-corrosive | Non-corrosive | Non-corrosive |
Table 3: the different surface treatment mode is respectively got 20 and is done PCT test (120 °, 0.2Mpa, 100% humidity), and it is as follows to calculate average result:
| 48 hours | 72 hours | 96 hours | 144 hours | 288 hours | 500 hours | |
| The present invention handles magnet and does not electroplate | Non-corrosive | Non-corrosive | Non-corrosive | Get rusty 8 | Get rusty 16 | Get rusty 20 |
| The commonsense method magnet is electroplated NI-CU-NI | Non-corrosive | Get rusty 1 | Get rusty 14 | Get rusty 20 | ??--- | ??--- |
| The present invention handles magnet re-plating NI-CU-NI | Non-corrosive | Non-corrosive | Non-corrosive | Non-corrosive | Non-corrosive | Non-corrosive |
Hence one can see that handles the salt mist test of the magnet do not electroplate and PCT result of the test through the inventive method all to electroplate NI-CU-NI than commonsense method magnet good, salt mist test and PCT result of the test can both reach 144 hours and 96 hours non-corrosives, and can reach the magnet of handling with the present invention program fully can directly use.Electroplate that NI-CU-NI can reach more than 1000 hours salt mist test and PCT test non-corrosive more than 500 hours for handling through the inventive method to add again, embodied to handle and add the NI-CU-NI great advantage aspect anticorrosion of electroplating again through the present invention.
Embodiment
Embodiment 1
Make the magnet of 45M of the metallurgy sintered method of ordinary powder:
1: with prescription is that Nd23%Pr7%Dy1%B1.0%CO0.5%Cu0.1%Al0.2%Fe67.2% (mass percent) is smelted into the thick steel ingot less than 25mm in vacuum melting furnace;
2: with in be broken into less than 20 purpose particles in the broken machine;
3: the powder that is broken into 3-5um with the airflow milling micro mist;
4: die mould becomes the cylindrical magnet of D14*30;
5: in vacuum sintering furnace 1080-1105 ℃ sintering 1-3 hour, and do 920 ° of timeliness 1-2 hours;
6: cylindrical grinding and microsection manufacture become the magnet of D14*1.5;
7: all magnets are made chamfering, and the pickling pre-treatment is directly electroplated NI-CU-NI through the magnet of 530 ℃ of timeliness;
8: magnet was handled 3 hours at the liquation of 530 ° of constant temperature of the M of 90wt%Zn-10wt%Al alloy, takes out magnet then and put into the cooler bin gas of band inert gas and quench to natural cooling below 85 ℃ from the M alloy, made to electroplate NI-CU-NI and handled equally again.
Embodiment 2
Magnet 530 ° of constant temperature of metal alloy of 90wt%Zn-10wt%Al and in addition the liquation of 100mpa pressure handled 1 hour, from metal alloy, take out magnet then and put into the cooler bin gas of band inert gas and quench, remake and electroplate NI-CU-NI and handle to natural cooling below 85 ℃.
All the other steps are with embodiment 1.
Claims (8)
1, a kind of highly corrosion resistant R-Fe-B magnet comprises R-Fe-B series magnet body, it is characterized in that described magnet body surface is coated with the non-magnetic metal alloy of one deck, and metal alloy also is penetrated into the magnet body interior; Described metal alloy is one or more of Zn, Al, Cu, Ag, Ga, Cr, Sb, Sn, Zr, Ti, Pb, Bi, In, Cd, Ca.
2, a kind of highly corrosion resistant R-Fe-B magnet according to claim 1 is characterized in that described magnet body surface is coated with thickness more than or equal to the non-magnetic metal alloy of 2um and be penetrated into the magnet body interior degree of depth more than or equal to 2um.
3, a kind of highly corrosion resistant R-Fe-B magnet according to claim 1, it is characterized in that described metal alloy is penetrated into rich rare earth phase of replacement and boron-rich phase in the described magnet body top layer, diffusion takes place or permeates the new alloy-layer of formation with boron-rich phase in metal alloy and rich rare earth mutually simultaneously.
4,, it is characterized in that the concentration that described metal alloy is penetrated in the described magnet body top layer along with the increase metal alloy of the degree of depth reduces gradually according to claim 1 or 2 or 3 described a kind of highly corrosion resistant R-Fe-B magnets.
5, the preparation method of a kind of highly corrosion resistant R-Fe-B magnet as claimed in claim 1 comprises according to the formulation ratio raw material and be smelted into steel ingot in vacuum melting furnace; Again with steel ingot with in be broken into particle in the broken machine; Be broken into powder with the airflow milling micro mist; Die mould becomes cylindrical magnet; At the vacuum sintering furnace sintering; Cylindrical grinding and section; All magnets are made chamfering, and the pickling pre-treatment is characterized in that the ambient temperature with 450 ℃～650 ℃ makes described alloying metal fusing and fully stirring; Put into the molten metal alloy solution and allow the metal alloy solution infiltration finishing magnet after the chamfering pickling; The treated magnet of taking-up is put into and is with the airtight cooler bin gas of inert gas air-cooled to quench from metal alloy solution, and natural cooling, gets product.
6, the preparation method of a kind of highly corrosion resistant R-Fe-B magnet according to claim 5 is characterized in that again finished product being made electroplating processes after obtaining described finished product.
7, the preparation method of a kind of highly corrosion resistant R-Fe-B magnet according to claim 5 is characterized in that the described magnet of finishing after the chamfering pickling puts into the molten metal alloy solution and allow metal alloy solution infiltration 0.5～10 hour.
8, the preparation method of a kind of highly corrosion resistant R-Fe-B magnet according to claim 5, it is characterized in that described magnet put into molten metal alloy solution in addition the liquation of 0～200mpa pressure handled 0.5～10 hour.
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Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102114536A (en) * | 2010-01-05 | 2011-07-06 | 北京中科三环高技术股份有限公司 | Method for improving corrosion resistance of surface of rare earth permanent-magnetic material of diffusion-plated fluoride |
| CN104112580A (en) * | 2013-04-16 | 2014-10-22 | 北京中科三环高技术股份有限公司 | Preparation method of rare earth permanent magnet |
| CN105551707A (en) * | 2016-02-25 | 2016-05-04 | 廊坊京磁精密材料有限公司 | Neodymium iron boron magnet raw material powder and treatment process therefor |
| CN108133820A (en) * | 2017-12-20 | 2018-06-08 | 赣州新瑞迪奥磁性材料有限公司 | The preparation method of the neodymium iron boron ring magnet of high temperature resistant radiation orientation or multipole orientation |
| CN109692963A (en) * | 2018-12-18 | 2019-04-30 | 宁波中杭磁材有限公司 | A kind of preparation method of the neodymium iron boron magnetic body of surface with corrosion-resistant finishes |
| CN109754984A (en) * | 2019-01-08 | 2019-05-14 | 朱景全 | A kind of monopole annular magnet and preparation method thereof |
-
2009
- 2009-05-26 CN CN200910116871A patent/CN101615463A/en active Pending
Cited By (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102114536A (en) * | 2010-01-05 | 2011-07-06 | 北京中科三环高技术股份有限公司 | Method for improving corrosion resistance of surface of rare earth permanent-magnetic material of diffusion-plated fluoride |
| CN102114536B (en) * | 2010-01-05 | 2015-05-20 | 北京中科三环高技术股份有限公司 | Method for improving corrosion resistance of surface of rare earth permanent-magnetic material of diffusion-plated fluoride |
| CN104112580A (en) * | 2013-04-16 | 2014-10-22 | 北京中科三环高技术股份有限公司 | Preparation method of rare earth permanent magnet |
| CN105551707A (en) * | 2016-02-25 | 2016-05-04 | 廊坊京磁精密材料有限公司 | Neodymium iron boron magnet raw material powder and treatment process therefor |
| CN105551707B (en) * | 2016-02-25 | 2018-05-22 | 廊坊京磁精密材料有限公司 | A kind of neodymium iron boron magnetic body raw material powder and its treatment process |
| CN108133820A (en) * | 2017-12-20 | 2018-06-08 | 赣州新瑞迪奥磁性材料有限公司 | The preparation method of the neodymium iron boron ring magnet of high temperature resistant radiation orientation or multipole orientation |
| CN109692963A (en) * | 2018-12-18 | 2019-04-30 | 宁波中杭磁材有限公司 | A kind of preparation method of the neodymium iron boron magnetic body of surface with corrosion-resistant finishes |
| CN109754984A (en) * | 2019-01-08 | 2019-05-14 | 朱景全 | A kind of monopole annular magnet and preparation method thereof |
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