CN1051865C - Rare earih magnet having excellent corrosion resistance - Google Patents
Rare earih magnet having excellent corrosion resistance Download PDFInfo
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- CN1051865C CN1051865C CN 87106209 CN87106209A CN1051865C CN 1051865 C CN1051865 C CN 1051865C CN 87106209 CN87106209 CN 87106209 CN 87106209 A CN87106209 A CN 87106209A CN 1051865 C CN1051865 C CN 1051865C
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- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01F—MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
- H01F1/00—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties
- H01F1/01—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties of inorganic materials
- H01F1/03—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties of inorganic materials characterised by their coercivity
- H01F1/032—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties of inorganic materials characterised by their coercivity of hard-magnetic materials
- H01F1/04—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties of inorganic materials characterised by their coercivity of hard-magnetic materials metals or alloys
- H01F1/047—Alloys characterised by their composition
- H01F1/053—Alloys characterised by their composition containing rare earth metals
- H01F1/055—Alloys characterised by their composition containing rare earth metals and magnetic transition metals, e.g. SmCo5
- H01F1/057—Alloys characterised by their composition containing rare earth metals and magnetic transition metals, e.g. SmCo5 and IIIa elements, e.g. Nd2Fe14B
- H01F1/0571—Alloys characterised by their composition containing rare earth metals and magnetic transition metals, e.g. SmCo5 and IIIa elements, e.g. Nd2Fe14B in the form of particles, e.g. rapid quenched powders or ribbon flakes
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- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01F—MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
- H01F1/00—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties
- H01F1/01—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties of inorganic materials
- H01F1/03—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties of inorganic materials characterised by their coercivity
- H01F1/032—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties of inorganic materials characterised by their coercivity of hard-magnetic materials
- H01F1/04—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties of inorganic materials characterised by their coercivity of hard-magnetic materials metals or alloys
- H01F1/047—Alloys characterised by their composition
- H01F1/053—Alloys characterised by their composition containing rare earth metals
- H01F1/055—Alloys characterised by their composition containing rare earth metals and magnetic transition metals, e.g. SmCo5
- H01F1/057—Alloys characterised by their composition containing rare earth metals and magnetic transition metals, e.g. SmCo5 and IIIa elements, e.g. Nd2Fe14B
- H01F1/0571—Alloys characterised by their composition containing rare earth metals and magnetic transition metals, e.g. SmCo5 and IIIa elements, e.g. Nd2Fe14B in the form of particles, e.g. rapid quenched powders or ribbon flakes
- H01F1/0572—Alloys characterised by their composition containing rare earth metals and magnetic transition metals, e.g. SmCo5 and IIIa elements, e.g. Nd2Fe14B in the form of particles, e.g. rapid quenched powders or ribbon flakes with a protective layer
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- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01F—MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
- H01F1/00—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties
- H01F1/01—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties of inorganic materials
- H01F1/03—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties of inorganic materials characterised by their coercivity
- H01F1/032—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties of inorganic materials characterised by their coercivity of hard-magnetic materials
- H01F1/04—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties of inorganic materials characterised by their coercivity of hard-magnetic materials metals or alloys
- H01F1/047—Alloys characterised by their composition
- H01F1/053—Alloys characterised by their composition containing rare earth metals
- H01F1/055—Alloys characterised by their composition containing rare earth metals and magnetic transition metals, e.g. SmCo5
- H01F1/057—Alloys characterised by their composition containing rare earth metals and magnetic transition metals, e.g. SmCo5 and IIIa elements, e.g. Nd2Fe14B
- H01F1/0571—Alloys characterised by their composition containing rare earth metals and magnetic transition metals, e.g. SmCo5 and IIIa elements, e.g. Nd2Fe14B in the form of particles, e.g. rapid quenched powders or ribbon flakes
- H01F1/0575—Alloys characterised by their composition containing rare earth metals and magnetic transition metals, e.g. SmCo5 and IIIa elements, e.g. Nd2Fe14B in the form of particles, e.g. rapid quenched powders or ribbon flakes pressed, sintered or bonded together
- H01F1/0577—Alloys characterised by their composition containing rare earth metals and magnetic transition metals, e.g. SmCo5 and IIIa elements, e.g. Nd2Fe14B in the form of particles, e.g. rapid quenched powders or ribbon flakes pressed, sintered or bonded together sintered
Abstract
An (Fe,Co)-B-R tetragonal type magnet and magnet alloy powder having a high corrosion resistance, which have a boundary phase stabilized by Co and Al against corrosion, and which consist essentially of: 0.2 - 3.0 at% Dy and 12 - 17 at% of the sum of Nd and Dy; 5 - 10 at% B; 0.5 - 13 at% Co; 0.5 - 4 at% Al; and the balance being at least 65 at% Fe. 0.1 - 1.0 at% of Ti and/or Nb may be present. The alloy powders can be stabilized.
Description
The Fe-B-R type rare-earth permanent magnet that the present invention relates to have high magnetic property (in the present invention, R represents to comprise the rare earth element of yttrium), particularly about permanent magnet based on rare earth element (R), boron (B) and iron (Fe), by choosing the special composition of component element, anti-corrosion characteristic is improved greatly.
Before this, three inventors of the present invention file an application with regard to improved high-performance permanent magnet, its performance is better than the highest traditional rare earth cobalt magnet of magnetic property, the i.e. Fe-B-R type permanent magnet of forming by key component iron (Fe), boron (B) and light rare earth element, abundant neodymium (Nd) and the praseodymium (Pr) of content in light rare earth element such as the natural resources, but without samarium (Sm) and cobalt (Co), their natural resources content seldom, commercial availability is unreliable, so valency expensive (Japanese Unexamined Patent Publication No 59-46008 and 59-89401 or EPA101552).
Foregoing invention human cobalt (Co) replaces part iron (Fe), has also successfully obtained another kind of Fe-B-R type permanent magnet, the above-mentioned magnetic alloy of the high what of its Curie temperature scope.The Curie temperature scope of general above-mentioned magnetic alloy is 300 ℃ to 370 ℃ (Japanese Unexamined Patent Publication No 59-64733 and 59-132104 or EPA106948).
In order to improve temperature characterisitic (particularly coercive force " iHc "), simultaneously contain cobalt Fe-B-R type (or rather with above-mentioned, i.e. (Fe, Co)-and the B-R type) rare-earth permanent magnet compares and keeps identical or high Curie temperature and higher (BH) max, foregoing invention people further contains cobalt Fe-B-R type rare-earth permanent magnet with regard to another kind and has proposed application, and its iHc has higher improvement, simultaneously, still kept very high (BH) max, its value is 25MGOc or higher.These can be with at least a at heavy rare earth element such as dysprosium (Dy), terbium (Tb) etc., part as the R component that contains cobalt Fe-B-R type rare-earth permanent magnet realizes that R mainly comprises light rare earth element such as Nd and/or Pr (Japanese Unexamined Patent Publication No 60-34005 or EPA).
Yet, having above-mentioned excellent magnetic energy, the permanent magnet of being made up of Fe-B-R type magnetic anisotropy sintered body comprises those rare earth elements and iron as main component, and they are easy to oxidation and often form stable oxide layer gradually in air.Because this cause when this permanent magnet carries out the magnetic circuit assembling, will be brought variety of issue and inconvenience in the oxide layer that magnet surface forms: the decline of magnetic circuit output; Inhomogeneous broadening effect in the magnetic circuit; And on the other hand, owing to the pollution that has caused various magnetic circuit peripheral units of peeling off of magnet surface oxide layer.
Therefore, in order to improve the anti-corrosion characteristic of above-mentioned Fe-B-R type permanent magnet, propose a kind of permanent magnet with non-corrosive metal layer already, lumarith is (the Japanese Unexamined Patent Publication No 58-162350) that the method for employing electroless plating or electrolysis plating is coated in magnet surface.And proposed another kind of permanent magnet with corrosion protection resin bed, it covers magnet surface (Japanese Unexamined Patent Publication No 58-171907) with spraying process or infusion process.
Yet, still have problems with this painting method, such as, because permanent magnet is the sintered body of relevant pore, in the micropore that acidity that giving before applying operation used in the processing or alkaline solution remain in sintered magnet, obviously this is easy to make magnet to be corroded over time; In addition, because the chemically-resistant response characteristic of magnet is poor, magnet surface is corroded in applying operation, thereby has reduced adhesion characteristic and anti-corrosion characteristic.
Further with regard to the spraying method of back, because coated with resins has directivity in this way, applying even resin on the whole surface of workpiece that need are handled needs a lot of treatment steps and time; When magnet shape was complicated, coating thickness was filmed just difficult more uniformly especially.In addition, adopt infusion process can make that resinous coat is in uneven thickness, the result causes the finished size precision of poor quality.
In addition, a kind of improved Fe-B-R type permanent magnet has also been proposed, can successfully overcome the intrinsic shortcoming of above-mentioned cladding process, spraying process and infusion process, and can keep stable anti-corrosion characteristic for a long time, this is anticorrosion layer (the Japanese patent application No. 59-278489 that is made up of various metal or alloy in the magnet surface vapour deposition, 60-7949, the corresponding present EPA0190461 of 60-7950 and 60-7951).Adopt this vapor deposition method, suppressed the oxidation of magnet surface, so that prevented the deterioration of magnetic property.And, owing to need not use chemical mordant etc., needn't worry fully to resemble therefore that chemical mordant can remain in the magnet the cladding process.The permanent magnetism physical efficiency of Chu Liing keeps its stability in long-time in this way.
Though adopt vapor deposition method very effective, but the shortcoming of himself arranged to the corrosion resistance of improving permanent magnet, for example, need particular processing equipment, productivity ratio is low, and it is quite expensive therefore handling in this way.
United States Patent (USP) 4588439 discloses a kind of Fe-B-R type permanent-magnet alloy, ftractures for fear of the sintered magnet that stands autoclave test, and its oxygen content is 6000 to 35000ppm (preferably 9000 to 30000ppm).Yet this alloy is because oxide layer need consume a lot of rare earth elements.Realize that complete inhibition needs 9000ppm oxygen, forming oxide layer in other words needs six times of expendable weights to the rare earth element of oxygen content.So a large amount of oxide layers is undesirable, because the existence of non magnetic oxide layer is unfavorable to magnetic property.And valuable rare earth element is consumed, and for example, the oxygen content of 10000ppm will make the rare earth element of 6% (weight) consume when forming oxide layer.
Therefore, the eager expectation in this field addresses the above problem.Furthermore, must carefully treat to avoid oxidation production process, raw material and semi-finished product exactly, this further causes the rising of producing cost.
The purpose of this invention is to provide a kind of Fe-B-R type permanent magnetic material with improved anti-corrosion characteristic.
Another object of the present invention provides a kind of Fe-B-R type permanent magnet that can show excellent anti-corrosion characteristic, and the improvement of its anti-corrosion characteristic is not by surface treatment but realize by determining that it is formed.
Another purpose of the present invention provides a kind of Fe-B-R type permanent magnet of durability excellence, keeps its high magnetic characteristic simultaneously.
Further aim of the present invention provides the high Fe-B-R type permanent magnet of a kind of temperature characterisitic.
Further purpose will obtain understanding in the text.
The present invention is based on the various researchs carried out Fe-B-R type permanent magnet composition aspect and the result of exploration, promptly by specifying neodymium and dysprosium as rare earth element (R), and definite boron, cobalt, aluminium and iron in magnet (or material) is formed certain content and the specific limited of phosphorus content, the corrosion resistance of permanent magnet (or material) is improved, this improvement is so remarkable, so that can't be realized by traditional permanent magnet.Can be further improved by titanium and/or the niobium that adds certain content.
In other words, according to ordinary circumstance of the present invention, here provide a kind of have excellent anti-corrosion characteristic (Fe, Co)-B-R four directions type rare-earth permanent magnet (or material), its basic composition is: dysprosium is 0.2-3.0at% (atomic percent), neodymium and dysprosium sum are 12-17at%, boron is 5-8at%, and cobalt is 0.5-13at%, and aluminium is 0.5-4at%, surplus is an iron, and it mainly is tetragonal mutually.Iron is at least 65at%, and iron and cobalt sum preferably are at least 75at%.
By following detailed description, the preferred embodiment of reference product and magnetic property, simultaneously with reference to accompanying drawing, above-mentioned purpose, other purposes and according to of the present invention (Fe, Co)-the specific composition of B-R type rare-earth permanent magnet (or material) can be more clear.
In the accompanying drawing:
Fig. 1 illustrates the pressure cooker result of the test, has represented to bubble or the material surface generation time that oxide powder continued up to the top layer;
Fig. 2 illustrates the Kesternich test result, has represented the relation between the variation of duration and per surface area example weight.
The curve representation of Fig. 3 and Fig. 4 when aluminium is respectively 2% and during 0at%, adds the effect of the per surface area weight change of cobalt to the duration under the condition of 80 ℃ * 90%R.H..
The curve representation of Fig. 5 and Fig. 6 when cobalt is 4at% and 0at% respectively, adds the effect of the per surface area weight change of aluminium to the duration under the condition of 80 ℃ * 90%R.H.:
The curve representation of Fig. 7 in the experimental atmosphere of 80 ℃ * 90%R.H., phosphorus content not simultaneously, cobalt and aluminium are to the effect of flux loss and duration;
The below will describe the present invention especially in detail.
(BH) max according to rare earth permanent-magnetic material of the present invention is 25MGOe or higher, and iHc is 10KOe or higher. (for sintered anisotropic magnet). Be that 125 ℃, relative humidity are the pressure cooker test (P. C.T.) carried out in 85% the atmosphere and are that 80 ℃, relative humidity are in the prolongation long duration test of carrying out in 90% the atmosphere in temperature in temperature, made the traditional F e-B-R type rare earth permanent-magnetic material that the aluminium undercoating is processed and further chromate is processed with those and compare, permanent-magnet material of the present invention has shown excellent especially anti-corrosion characteristic.
In addition, except said components, add titanium and/or the niobium of 0.1-1.0at%, rare-earth permanent magnet of the present invention can improve its magnetic property (the particularly rectangular degree of demagnetizing curve) and (BH) max thereof, and does not reduce excellent anti-corrosion characteristic.
Do not contain in alloy in the situation of cobalt and aluminium, the composition of the Grain-Boundary Phase of this Fe-B-R type rare-earth permanent magnet is: boracic but have the iron of a small amount of atomic percent, the rich R phase that mainly is made of rare earth element and the high atomic percent of boron content to be approximately 40% or more R not1+εFe
4B
4Phase. Thus, the corrosion resistance of Fe-B-R type rare-earth permanent magnet is poor, and to be considered to mainly be because the existence of above-mentioned rich R phase, because its main component active rare earth element that is chemical property.
In the situation according to Fe-B-R type permanent magnet of the present invention, can think that cobalt and aluminium in the Grain-Boundary Phase enters above-mentioned rich R and forms mutually heterogeneously, this is based on the special control to cobalt and aluminium content. Help so the corrosion proof improvement of Grain-Boundary Phase and can not damage magnetic property.
The magnetic property of Fe-B-R type permanent magnet (or magnetic material) is mainly derived from by chemical structural formula R2Fe
14The Fe-B-R square intermetallic compound that B represents. In general, in order to obtain the high magnetic anisotropy sintered permanent magnet of practical magnetic property, must carefully select the magnet composition range, make it than stoichiometric composition R2Fe
14The comparatively rich R of B and rich B (particularly in the inadequate scope of R, the α in alloy and/or the sintered magnet-iron precipitate causes that magnetization is easy to turn to the result to cause coercivity to descend).
In rich R and rich B scope, exist rich R phase that major metal R forms and one by R1+εFe
14B
4The rich R phase that forms, this has effect to sintering characteristic and coercitive improvement. Particularly through oversintering (and further aging), rich R phase is so that the crystal boundary of tetragonal grain is level and smooth.
Disclose, corrosion resistance is main relevant with this rich R borderline phase. " R " of rich R in mutually is highly susceptible to by the oxygen in the ambient air and/or moisture oxidation. Further, if do impurity with carbon (C) and/or chlorine (Cl), they with the carbide of R or chloride exists and will be easily with atmosphere in moisture react and decompose (so in general, should keep low carbon and chlorinity).
R becomes nonmagnetic R oxide layer (as R
2O
3), descend along with increasing of oxide layer causes magnetic property (particularly Br and (BH) max can descend gradually).Yet if still have a considerable amount of R (promptly more than exist as the R oxide), this prepares magnet to sintering is essential, that is to say if R content is big, and the allowance of oxygen also can be correspondingly big so.But, can cause non magnetic a large amount of existence mutually if R increases with oxygen content, make Br and (BH) max reduce.So far, because R content is restricted (common in reality), when having a large amount of oxygen, the amount of R will be short, and this finally can cause coercitive completely losing.
According to the present invention, result from the problems referred to above of oxidation of rich R phase (perhaps usually said borderline phase), can be resolved by in component, mixing a certain amount of cobalt and aluminium.Cobalt and aluminium sum are in the ratio of the content of rare earth element (R ') (or plan content) in the borderline phase: (Co+Al)/and R ' particular importance.By controlling this ratio, contained rare earth element can be stablized in the borderline phase.Considerable cobalt and aluminium content and R form stable intermetallic compound (as NdCo
3, Nd
3Co
7Deng, generate the aluminum contained compound of determining here as solid solution), this is favourable to corrosion resistance.
Note having formed a certain amount of R here
2(Fe
1Co)
14B four directions phase (can think that a part of aluminium has occupied the position of iron and formed R in this tetragonal structure
2(Fe.Co.Al)
14B).These compounds are at R
2Fe
14Improved corrosion resistance on the basis of B phase.
(Co+Al)/span of R ' 0.5-10 (being more preferably 0.7-5) preferably.Being lower than 0.5 corrosion resistance will not have enough improvement, thereby and exceed 10 sintering characteristics and will worsen and cause iHc to descend.
As the guide of control, R ' content can roughly be calculated by following formula:
Here A is the middle mutually element total content in four directions, and RO is R oxide (R in magnet or the material
2O
3) amount (atomic percent).
By measuring, such as the numerical value that can determine R ', Co and Al with X-ray microanalyzer (XMA) etc.
By mixing cobalt and aluminium, not only can make sintering finished but also the corrosion resistance of alloy material (particularly powder) is significantly improved.For example, adopt direct-reduction process by reducing agent such as calcium, the alloy powder that is obtained by rare earth oxide mixes cobalt and aluminium can reduce oxygen content.Therefore, the present invention significantly improves the applicable industries product and the use thereof of general Fe-B-R type permanent magnet.
Below will set forth the reason that the present invention limits the content range of each component of rare-earth permanent magnet.
When dysprosium contains quantity not sufficient 0.2at%, do not observe iHc and (BH) raising of max.Otherwise when its content exceeded 3.0at%, iHc improved.Yet, because the natural resources amount usable of dysprosium is very little, so it is very expensive and raised the product cost of permanent magnet unfriendly.For this cause, its content is limited in the scope of 0.2at% to 3.0at%, perhaps better in the scope of 0.2at% to 2.0at%.Dysprosium also helps improving the temperature characterisitic of magnet, after reversible loss of magnetic flux especially at high temperature and the high-temperature process under the situation of the irreversible loss of magnetic flux.
When neodymium and dysprosium sum (being the total content of rare earth element) when being less than 12at%, will separate out α-iron in the metallic compound of main phase, cause iHc to descend suddenly thus.On the other hand, when its content exceeds 17at%, if do not have a large amount of cobalts and aluminium (big like this amount is influential to magnetic property), then can be owing to a large amount of existence of rich R phase, and make the corrosion resistance of the basic ternary synthetic of Fe-B-R worsen.Owing to this reason, neodymium and dysprosium sum are limited in the scope of 12at% to 17at%, or better 12.5at% to 15at% (can obtain 30MGOe or higher and good corrosion resistance).Neodymium content is preferably got 11-16at% and (is got 12～14.5at%) better.In order to obtain enough rich neodymium borders and to save dysprosium (latter is applicable to that also neodymium content is 16at%, and neodymium content should be got 11at% at least).Yet, can partly replace neodymium and can not influence magnetic property and corrosion resistance with praseodymium.Equally, as commercially available neodymium material, can partly adopt the mischmetal(l) that comprises neodymium, praseodymium and cerium.
When boron contained quantity not sufficient 5at%, iHc dropped to 10KOe or lower unfriendly.On the other hand, its content surpasses 10at%, and iHc rises but Br descends, to such an extent as to can not obtain 25MGOe or higher (BH) max.In addition, boron is during more than 10at%, and non magnetic rich B increases quite a lot of mutually.Owing to these reasons, the scope that boron content is limited in 5at% to 10at% (is preferably in 6～8at%).
Except can improving saturation magnetization Is, cobalt is also for improving Curie temperature, and the oxidation resistance of improving the ageing-resistant ability of product and raw material (alloy, especially powder) is effective.When cobalt content is lower than 0.5at%, have little effect to improving Curie temperature and improving product (or material) corrosion resistance.Otherwise when its content surpassed 13at%, the cobalt part was gathered, and formed the high density agglomerate at crystal boundary.As a result, cause that cobalt content is that 30at% or higher ferromagnetism R (Nd.Dy)-Co compound are separated out, this makes the commutation in the Fe-B-R type rare-earth permanent magnet of the present invention, and iHc descends.Owing to this reason, cobalt content is limited in the scope of 0.5at% to 13at%, or based on above-mentioned opinion, is preferably in 1at% to 10at%.In addition, cobalt content is 5at% or when higher, the temperature coefficient of residual magnetic flux density Br is 0.1%/℃ or lower.
Aluminium cooperates with cobalt, utilizes its co that has, and the corrosion resistance of raising iHc particularly being improved product is effective.The effect of this iHc of improvement is tending towards along with increasing of cobalt addition descending.When aluminium content was lower than 0.5at%, the effect that iHc improves and product (or material) corrosion resistance is improved can not be satisfactory.Otherwise its content surpasses 5at%, and is effective to improving iHc, but Br is lower and (BH) max be lower than 25MGOe.From the angle of balance, aluminium content is limited in the scope of 0.5at% to 5at%, perhaps is preferably in 0.5at% to 3at%.
Owing to add aluminium, make titanium or niobium to Br and (BH) max a kind of additional reduction effect is arranged.When titanium or content of niobium deficiency 0.1at%, the raising of Br does not have enough effects.On the other hand, its content surpasses 1.0at%, and titanium or niobium combine the boride that forms titanium or niobium with boron in magnetic alloy, cause the minimizing of the boron that is inevitable concerning magnetic alloy thus, and (therefore short iron) simultaneously, causes the decline of iHc.Owing to these reasons, titanium and/or content of niobium are limited in the scope of 0.1at% to 1.0at%, perhaps, are preferably in the scope of 0.2at% to 0.7at%.In vanadium, molybdenum, tungsten, tantalum, hafnium, the zirconium each can be got the content of 0.1～1.0at%, works as titanium or niobium.
Carbon also has a significant impact the corrosion resistance of permanent magnet.Carbon can R carbide exist, it be easy to atmosphere in reaction of moisture and cause reduction.When its content surpassed 2000ppm, corrosion resistance sharply descended and is difficult to obtain practical permanent magnet.Therefore its content should be equal to or less than 2000ppm, preferably equals or low 1000ppm, is more preferably and is equal to or less than 700ppm.Carbon derives from raw material as impurity often.For example iron, ferroboron or rare earth element, be sometimes by preparation section bring into (as from compression molding device intrinsic carbon, or come from solvent that is used for abrasive dust etc.).
In rare-earth permanent magnet of the present invention or alloy material, the surplus in the component except above-mentioned element is iron and unavoidable impurities.
Iron content should be 65at% at least.Because be lower than this quantity and be difficult to reach 25MGOe or higher.Iron content is preferably got 81at% at the most, because if be higher than this quantity, will separate out α-iron.Therefore iron content is preferably in 68-81at%.Should be noted that cobalt can partly replace the iron in the basic Fe-B-R tetragonal structure, form (Fe, Co)-the B-R tetragonal structure.
Generally do not wish to exist oxygen, because the R of its meeting consume expensive generates nonmagnetic oxide.Because the R chemical property is active, after sintering, certainly exists oxygen in the magnet, and nearly all be (as R with the R oxide through 1000 ℃ or higher temperature
2O
3) exist.Yet oxygen is inevitably as a kind of impurity, because general rare earth element is very easy to by oxygen or water oxidation.Make raw material, preparation section, semi-finished product and finished product break away from oxygen or moisture (being air) is very difficult.Therefore, based on the magnetic property and the consideration of saving R (economy), in practice or on the industrial accessible level, it is low as much as possible that oxygen content should keep.Like this, oxygen content should remain on or be lower than 10000ppm, preferably is equal to or less than 8000ppm (better being equal to or less than 6000ppm).
Other impurity may also have phosphorus, sulphur, manganese, nickel, silicon, copper, chromium etc., and these impurity can be sneaked into alloy compositions inevitably in industrial processes.Under the condition that does not influence essential magnetic property, these impurity allow to be present in magnet of the present invention or material.
Chlorine also may exist as impurity, as when adopting wet method to carry out alloy pulverizing use organochlorine compound solvent (trichloroethylene etc.).Chlorine exists as the chloride of R like this, and it is easy to be decomposed by airborne moisture.Therefore, if there is chlorine, its content should be at 1500ppm or lower, preferably 1000ppm or lower.
Nitrogen may be sneaked into by preparation technology, and as with in the jet powder process of nitrogen as abrasive media, nitrogen content approximately is 1000ppm, and when adopting ball mill to carry out wet grinding, the nitrogen content that uses solvent to bring is very low, as is lower than 100ppm.If contain nitrogen in the magnet, then can form the nitrogenize neodymium, it is very easy to react with water.Therefore, wish preferably its content to be controlled at 2000ppm or lower, be more preferably at 1000ppm or lower.
According to preferred viewpoint of the present invention, the magnet solvent is: 12 to 14.5at% neodymium, 0.2 to the dysprosium of 2.0at% (scope of neodymium and dysprosium sum be 12.5 to 15at%), 6 to 8at% boron, 1 to 10at% cobalt, 0.5 to the aluminium of 3at%, 1000ppm or lower carbon, surplus is iron (68-81at%) and unavoidable impurities.Wherein main phase (preferably accounting for 85VoL% at least) is (Fe, Co)-B-R tetragonal structure, and present the excellent magnetism energy, its (BH) max and iHc are respectively 30MGOe or higher and 13KOe or higher, with as the anisotropy sintered body, and also present very high corrosion resistance.
Merit attention, if carry out suitable burin-in process, the magnetic property of magnet will be higher.
Further, according to permanent magnet of the present invention (or material) if comprise R with tetragonal structure
2(Fe, Co)
14The Type B compound is as main phase, and have in rich R is heterogeneous, comprise 5 to 30at% cobalt and 5at% or lower aluminium crystal boundary mutually, will demonstrate best corrosion resistance.Rich R heterogeneous by a rich R who does not contain aluminium and contain cobalt mutually and another both contained the rich R phase composition that aluminium contains cobalt.When the crystallite dimension of magnet approximately was 1 μ m-100 μ m (preferably 2-30 μ m), magnet had significantly high magnetic property.
For the person skilled in the art who makes this area can implement the present invention, provide following examples.
Embodiment example 1
As agglomerated material, it is the electrolytic iron of 99.9% (purity is weight percentage) that raw material use purity, ferroboron (boron is 20%), and neodymium (is praseodymium greater than 97% surplus), purity is greater than 99% dysprosium, cobalt, aluminium and titanium, contains niobium and be 67% ferroniobium.These components are given separately with them after the certainty ratio mixing, and every kind of mixture forms alloy by the high-frequency heating fusing, and then the alloy of fusing casts in water cooled copper mould, the result, and acquisition has the alloy blank of the various compositions shown in following table 1 thus.A certain amount of silicon, manganese, copper and chrome liquor from ferroboron are sneaked into.These elements have improved the rectangle degree of iHc and demagnetization curve, and this is manganese, copper and the chromium of 200-3000ppm based on silicon that contains 300-5000ppm in the magnet and total amount seemingly.
Subsequently, blank is smashed to pieces roughly, then in ball mill, carried out the wet method abrasive dust, obtain particle mean size thus and be 3 microns powder by chlorotrifluoroethane with bruisher.
The metal pattern of each powder threading pressure setting, apply the parallel magnetic field of 12KOe, with 1.5 tons/Cm
2Pressure carry out moulding in direction perpendicular to magnetic field.Then, pressing stampings sintering two hours in argon atmospher, in 1040 ℃ to 1120 ℃ the temperature range, make its cooling then.At 600 ℃ sintered body is carried out further burin-in process subsequently.The result obtains to be of a size of the permanent magnetic material sample of 20mm * 10mm * 8mm, it is applied at least the magnetic field of 25KOe magnetize.
To the measurement result of the magnetic property of thus obtained permanent magnet shown in following table 1.The content of cobalt and aluminium utilizes the X-ray microanalysis instrument to determine, like this, can obtain being in the component analysis of the rich R phase of crystal boundary.The calculating of analysis result has been provided the mean value of the crystal boundary phase component that is in triple point substantially.
Carry out magnetic property after magnetizing and measure, the result can see Table 1.Determine that by the present invention the magnetic property that the Fe-B-R type permanent magnet of component is had is equal to or higher than traditional Fe-B-R type permanent magnet.
Table 1
| Component (at%) | Rich R mutually in (at%) | Magnetic property | ||||||||||||||
| Iron | Neodymium | Dysprosium | Boron | Cobalt | Aluminium | Titanium | Niobium | Carbon (ppm) | Oxygen (ppm) | Cobalt | Aluminium | Br (KG) | iHc (KOe) | (BH)max MGOe | ||
| The | 1 2 3 4 | 67.5 70.5 69.5 73 | 14 14 14 14 | 1.5 0.5 0.5 0.5 | 7 7 7 7 | 8 6 6 4 | 2 2 2 1 | - - 1 - | - - - 0.5 | 800 650 270 430 | 5500 6200 3100 4800 | 22-29 15-29 5-25 5-23 | 0.5-1.5 0.4-1.2 0.4-1.5 0.3-1.0 | 11.4 12.1 12.5 12.4 | 20 16.0 14.8 15.2 | 31.1 36.0 36.2 36.4 |
| Comparative Examples | 5 6 7 8 | 77.5 78 72.5 77.5 | 14 14 14 14 | 1.5 0.5 0.5 0.5 | 7 7 7 7 | - - 6 - | - - - 1 | - - - - | - 0.5 - - | 800 1200 1100 700 | 7500 5300 3800 4400 | 0 0 0-28 0 | 0 0 0 0 | 11.5 12.3 12.6 12.5 | 19.4 15.8 10.5 15.4 | 32.0 36.0 37.0 35.2 |
Example 2
To some test piece that obtains by above example 1, carry out carrying out surface treatment with chromate again after undercoating handles with aluminium, obtain doing the surface-treated sample thus, on the other hand, remaining sample does not process, as surperficial untreated samples.Then every group of sample done pressure cooker test (P.C.T.), experimental condition is atmosphere relative humidity 85%, 125 ℃ of temperature, pressure 2Kgf/Cm
2Through pressure cooker test, because the erosion of crystal boundary phase, cubic crystal grain separates with sample surfaces and generates the grey powder.Therefore, the pressure cooker test shows, corrosion proof evaluation master is based on the stable of borderline phase.
Peel off from sample surfaces according to surface treatment and to produce the needed time evaluation test of pore result, perhaps produce the needed time of powder and estimate according to the material sample surface.Fig. 1 has provided result of the test.
As seen from Figure 1, did the surface-treated conventional permanent magnet in order to improve corrosion resistance with those and compare, permanent magnet of the present invention does not carry out any surface treatment but demonstrates excellent especially anti-corrosion characteristic.Do not have the sample of cracking present almost with test before identical magnetic property, and measure the sample of cracking.Example 3
That obtain and do not do and be numbered 2,3,6,7 test piece in the surface-treated table 1 to those by top example 1, carry out Kesternich test.Sample is remained under the atmosphere of 90% relative humidity, the 80 ℃ of temperature (the weather breakdown test of acceleration) for a long time, sample is remained in the above-mentioned atmosphere, come the evaluation test result according to the increase and the relation between the retention time of each sample per surface area oxide layer quantity.Result of the test is seen Fig. 2.As a result, the sample through this test produces red rust.Therefore, this is a kind of accelerated test that shows in the weather endurance on average operating lower magnet surface.That is to say that except the borderline phase of magnet surface, the corrosion resistance of tetragonal structure also is to estimate according to above-mentioned test.So, to estimate fully for the corrosion proof of this type of magnet, this test is essential.
As seen from Figure 2, have very outstanding corrosion resistance according to permanent magnet of the present invention, this degree is that traditional Fe-B-R type rare-earth permanent magnet is inaccessiable.Example 4
Do not carry out the surface-treated sample according to component preparation as shown in table 2, utilize jet powder process method to pulverize in the nitrogen that contains 1000ppm oxygen, other method with example 1 is identical.Sample 12-14 in the table 2 does not contain cobalt and aluminium.Utilize autocrave, in 180 ℃ saturated steam atmosphere, these samples are carried out 16 hours Kesternich test.All carry out magnetic property before and after the Kesternich test and measure, those test the preceding table 3 that the results are shown in, and also example weight loss and the relation of duration are measured, and are as shown in table 3.
By table 2 and table 3 as can be seen, contain the sample that is numbered 9-11 of cobalt and aluminium, do not have the loss in weight and cracking.And the sample that is numbered 12-14 is divided into two groups according to the total content of rare earth element, and one group has the loss in weight and face checking and another group does not have.
There is not the sample of cracking within measure error, to show the magnetic property of same level, even after the autocrave test.
So, can conclude, by cobalt and the aluminium that mixes specific quantity, the corrosion resistance of Fe-B-R type permanent magnet is significantly improved.In addition, the total amount of the rare earth element in magnet or the material is very big to the corrosion resistance influence of Fe-B-R type permanent magnet.In general, be in rare earth element in the Fe-B-R type magnet borderline phase with the increasing and increase of R total amount, this surplus of R or excessive corrosion resistance is had adverse influence, but can eliminate this adverse effect fully by mixing cobalt and aluminium.Can believe, cobalt and aluminium can stability boundaris mutually.Can confirm further that the common existence of cobalt and aluminium can make the nitrogen content of sintered magnet be reduced to not contain in the basic magnet of cobalt and aluminium half to 1/3rd.
Can also think even that when not containing cobalt and aluminium if the total content of R is no more than about 14at% (and carbon content is low), Fe-B-R type permanent magnet just can not ftracture.Can think that this is owing to there not being excessive rich R phase in the borderline phase.
In addition, for anti-corrosion or cracking, it is uncertain that the absolute quantity of oxygen can be considered, and no matter contains the situation of cobalt and aluminium or does not contain the situation of cobalt and aluminium.On the contrary, the definite key element that suppresses corrosion is the control to borderline phase, and this can be by stablize or passing through the existence of the excessive rich R borderline phase of elimination with cobalt and aluminium, promptly more than being necessary minimum number to reaching required high magnetic characteristics.In view of this consideration, containing together with admissible impurity level is that the Fe-B-R type permanent magnet component of 14at% or lower R also will be as a kind of stable solvent (still in interior total amount, must be noted that solvent can be further stablized in the existence of cobalt and aluminium, even also be like this) to material.
Table 2
| No. | Component (at%) | Oxygen | Carbon |
| Nd-dy-fe-b cobalt aluminium | |||
| 9 10 11 12 13 14 | 15.5 0.5 69 7 6 2 14.5 0.5 70 7 6 2 13.5 0.5 71 7 6 2 15.5 0.5 77 7 - - 14.5 0.5 78 7 - - 13.5 0.5 79 7 - - | 6800 5500 5200 7200 6400 5500 | 170 220 190 240 220 180 |
Table 3
Example 5
| Br iHe (BH)max (KG) (KOe) (MGOe) | The loss in weight (%) | |
| 9 10 11 12 13 14 | 11.9 17.1 34.2 12.1 16.5 35.7 12.5 15.7 36.9 12.0 14.1 34.9 12.5 12.8 37.6 12.7 9.1 37.2 | 0 0 0 17％ 1％ 0 |
According to component as shown in table 4 (other is identical with example 1), preparation magnet sample, the content and the magnetic property of measurement oxygen and carbon, as shown in table 4.In relative humidity (R.H.) is 90% atmosphere, under 80 ℃ the temperature sample is tested, and the weight change of measuring samples per surface area.The result is shown in Fig. 3 to 6.
It is 2at% that Fig. 3 has provided aluminium content, when cobalt content changes at 0-6at%, and the variation of example weight.When not containing cobalt, the rate of corrosion of being represented by weight rate is big, and along with the increasing of cobalt content, becomes very low through the rate of corrosion behind the certain hour.
Fig. 4 provided do not contain aluminium and cobalt content when 2-6at% changes, the variation of example weight.Weight rate continuing and descend in time, along with increasing of cobalt content, downward trend strengthens.Compare with Fig. 3, the Fig. 4 that does not contain aluminium shows bigger weight change (rising).This trend is more obvious in Fig. 5 and Fig. 6, and Fig. 5 and Fig. 6 have provided the effect that is respectively 4at% and 0% aluminium when (promptly not containing aluminium) when cobalt content in other words.When not containing cobalt (Fig. 6), test has no significant effect to weight change to mix aluminium.And when containing cobalt (Fig. 5), the weight change amount increases with aluminium content and reduces.According to this fact, prove that having of aluminium helps corrosion proof improvement.
In addition, according to the result of table 4, when containing a spot of aluminium (as 1at%), iHc is significantly improved.Though when not containing aluminium, iHc increases and is tending towards descending with cobalt.
Mistake as discussed above, the common existence of cobalt and aluminium is to improving corrosion resistance and providing high magnetic characteristics that significant collaborative effect is all arranged in the Fe-B-R type permanent magnet.Example 6
Adopt those to have the blank that is numbered 15 to 17 component in the table 4, prepare the different sample of carbon content according to following steps, (1) as abrasive media or carrier blank is carried out jet powder process with nitrogen, (2) with solvent (Organic fluoride solvent, as polytetrafluoroethylene) as crushing medium, the pulverizing of taking ball-milling method to make with extra care, and/or (3) mix paraffin to adjust carbon content to the sample of determining.
The table 5 that the results are shown in that comprises the magnetic property that records.By applying the external magnetic field that intensity is at least 25KOc, sample is done further magnetized.Subsequently, in the atmosphere of 90%R.H., carry out weather corrosion breakdown test under 80 ℃ the temperature, utilize fluxmeter to measure the variation of magnetic flux.The result as shown in Figure 7.
As seen from Figure 7, general the increasing and increase of flux loss with carbon.But the flux loss rate obviously reduces when containing aluminium, even also like this when carbon increases, and particularly carbon is approximately 500ppm or more.
By the foregoing description as can be known, the present invention can save and be used to improve corrosion proof surface treatment.Can also carry out further surface treatment.Yet the surface treatment that is used for corrosion protection can quite be simplified, and is just enough as carry out resin impregnation with epoxy resin or similar resin.
So far, the invention has been described for reference example.Yet must be noted that in claims of the present invention main points or scope, those skilled in the art can make various changes and distortion.
Table 4
| Component (at%) | Impurity (ppm) | Magnetic property Br (BH) max iHc | |||||||||
| No. | Neodymium | Dysprosium | Iron | Boron | Cobalt | Aluminium | Oxygen | Carbon | (KG) | (MGOe) | (KOe) |
| 15 | 14 | 0.5 | 70.5 | 7 | 6 | 2 | 2400 | 340 | 11.8 | 33.6 | 16.1 |
| 16 | 14 | 0.5 | 71.5 | 7 | 6 | 1 | 2900 | 360 | 12.2 | 35.6 | 14.5 |
| 17 | 14 | 0.5 | 72.5 | 7 | 6 | 0 | 2700 | 330 | 12.6 | 37.7 | 10.1 |
| 18 | 14 | 0.5 | 72.5 | 7 | 4 | 2 | 2700 | 290 | 11.7 | 33.0 | 16.6 |
| 19 | 14 | 0.5 | 73.5 | 7 | 4 | 1 | 2600 | 330 | 12.3 | 36.1 | 14.7 |
| 20 | 14 | 0.5 | 74.5 | 7 | 4 | 0 | 2900 | 300 | 12.7 | 38.1 | 12.2 |
| 21 | 14 | 0.5 | 74.5 | 7 | 2 | 2 | 2000 | 350 | 11.8 | 33.7 | 16.9 |
| 22 | 14 | 0.5 | 75.5 | 7 | 2 | 1 | 2800 | 350 | 12.4 | 36.6 | 15.1 |
| 23 | 14 | 0.5 | 76.5 | 7 | 2 | 0 | 3300 | 340 | 12.7 | 38.5 | 12.7 |
| 24 | 14 | 0.5 | 76.5 | 7 | 0 | 2 | 3000 | 330 | 12.0 | 34.2 | 17.2 |
| 25 | 14 | 0.5 | 77.5 | 7 | 0 | 1 | 2900 | 350 | 12.3 | 36.1 | 16.2 |
| 26 | 14 | 0.5 | 78.5 | 7 | 0 | 0 | 3300 | 350 | 12.7 | 38.7 | 14.2 |
Table 5
| Component (at%) | Impurity (ppm) | Magnetic property Br (BH) max iHc | |
| No. | Nd-dy-fe-b cobalt aluminium | Oxygen carbon | (KG) (MGOe) (KOe) |
| 27 | 14 0.5 70.5 7 6 2 | 6500 170 | 12.1 34.9 16.3 |
| 28 | 14 0.5 70.5 7 6 2 | 2000 340 | 12.0 34.3 16.0 |
| 29 | 14 0.5 70.5 7 6 2 | 3400 610 | 12.0 34.4 15.7 |
| 30 | 14 0.5 70.5 7 6 2 | 3700 790 | 12.0 34.8 15.4 |
| 31 | 14 0.5 71.5 7 6 1 | 6000 170 | 12.5 34.8 16.0 |
| 32 | 14 0.5 71.5 7 6 1 | 2200 330 | 12.4 36.9 13.8 |
| 33 | 14 0.5 71.5 7 6 1 | 3600 620 | 12.5 37.3 14.0 |
| 34 | 14 0.5 71.5 7 6 1 | 3400 830 | 12.4 37.1 13.5 |
| 35 | 14 0.5 72.5 7 6 0 | 5800 240 | 12.9 39.9 11.8 |
| 36 | 14 0.5 72.5 7 6 0 | 2200 350 | 12.8 39.0 11.2 |
| 37 | 14 0.5 72.5 7 6 0 | 3700 550 | 12.9 39.4 11.1 |
| 38 | 14 0.5 72.5 7 6 0 | 3500 760 | 12.9 39.8 10.6 |
Claims (20)
1. produce have highly corrosion resistant and have by cobalt and aluminium make it stable borderline phase resist corrosion (Fe Co)-method of B-R four directions type permanent magnet, the method is characterized in that to comprise:
The alloy of mainly being made up of following component is provided:
12-14.5 atom % neodymium and 0.2-3.0 atom % dysprosium, the summation of neodymium and dysprosium is 12.5-15 atom %;
6-8 atom % boron;
0.5-8 atom % cobalt;
0.5-3 atom % aluminium;
The content of objectionable impurities carbon is no more than 1000ppm;
Surplus is at least the iron of 68 atom %;
The content of objectionable impurities chlorine is no more than under the condition of 1500ppm in the powder that forms, and carries out wet-milling with the chlorine-containing organic compounds solvent, with described alloy grind into powder;
The content that the content of objectionable impurities carbon is no more than 1000ppm and objectionable impurities chlorine in sintered body is no more than under the condition that 1500ppm forms sintered body, and the described powder of sintering makes it stable borderline phase by cobalt and aluminium and resists corrosion to provide.
2. be used to produce have highly corrosion resistant and have by cobalt and aluminium make it stable borderline phase resist corrosion (Fe Co)-preparation method of the alloy powder of B-R four directions type permanent magnet, the method is characterized in that to comprise:
The alloy of mainly being made up of following component is provided:
12-14.5 atom % neodymium and 0.2-3.0 atom % dysprosium, the summation of neodymium and dysprosium is 12.5-15 atom %;
6-8 atom % boron;
0.5-8 atom % cobalt;
0.5-3 atom % aluminium;
The content of objectionable impurities carbon is no more than 1000ppm;
Surplus is at least the iron of 68 atom %;
The content that the content of objectionable impurities carbon is no more than 1000ppm and objectionable impurities chlorine in the powder that forms is no more than under the condition of 1500ppm, carry out wet-milling with the chlorine-containing organic compounds solvent, with the alloy grind into powder that forms, make it stable borderline phase by cobalt and aluminium and resist corrosion to provide.
3. according to the method for claim 1 or 2, wherein cobalt is no more than 6 atom %.
4. produce have highly corrosion resistant and have by cobalt and aluminium make it stable borderline phase resist corrosion (Fe Co)-method of B-R-four directions type permanent magnet, the method is characterized in that to comprise:
The alloy of mainly being made up of following component is provided:
12-14.5 atom % neodymium and 0.2-3.0 atom % dysprosium, the summation of neodymium and dysprosium is 12.5-15 atom %;
6-8 atom % boron;
0.5-8 atom % cobalt;
0.5-3 atom % aluminium;
The content of objectionable impurities carbon is no more than 1000ppm;
Surplus is at least the iron of 68 atom %;
The content of objectionable impurities nitrogen is no more than under the condition of 2000ppm in the powder that generates, and carries out jet grinding in nitrogen, with described alloy grind into powder;
The content that the content of objectionable impurities carbon is no more than 1000ppm and objectionable impurities nitrogen in sintered body is no more than under the condition that 2000ppm forms sintered body, and the described powder of sintering makes it stable borderline phase by cobalt and aluminium and resists corrosion to provide.
5. be used to produce have highly corrosion resistant and by cobalt and aluminium make it stable borderline phase resist corrosion (Fe, Co)-preparation method of the alloy powder of B-R-four directions type permanent magnet; The method is characterized in that and comprise:
The alloy of mainly being made up of following component is provided:
12-14.5 atom % neodymium and 0.2-3.0 atom % dysprosium, the summation of neodymium and dysprosium is 12.5-15 atom %;
6-8 atom % boron;
0.5-8 atom % cobalt;
0.5-3 atom % aluminium;
The content of objectionable impurities carbon is no more than 1000ppm;
Surplus is at least the iron of 68 atom %;
The content of objectionable impurities nitrogen is no more than under the condition of 2000ppm in the powder that forms, and carries out jet grinding in nitrogen, with the alloy grind into powder that forms, makes it stable borderline phase by cobalt and aluminium and resists corrosion to provide.
6. according to the method for claim 4 and 5, wherein grind into powder is that nitrogen content is no more than under the condition of 1000ppm and carries out in the powder that forms.
7. according to the method for claim 4, wherein sintering is that nitrogen content is no more than under the condition of 1000ppm and carries out in the sintered body that forms.
8. produce have highly corrosion resistant and have by cobalt and aluminium make it stable borderline phase resist corrosion (Fe Co)-method of B-R-four directions type permanent magnet, the method is characterized in that to comprise:
The alloy of mainly being made up of following component is provided:
12-14.5 atom % neodymium and 0.2-3.0 atom % dysprosium, the summation of neodymium and dysprosium is 12.5-15 atom %;
6-8 atom % boron;
0.5-8 atom % cobalt;
0.5-3 atom % aluminium;
The content of objectionable impurities carbon is no more than 1000ppm;
Surplus is at least 68% iron;
The content that the content of objectionable impurities carbon is no more than 1000ppm and objectionable impurities chlorine in the powder that forms is no more than under the condition of 1500ppm, carries out wet-milling with solvent, with described alloy grind into powder;
The content that the content of objectionable impurities carbon is no more than 1000ppm and objectionable impurities chlorine in sintered body is no more than under the condition that 1500ppm forms sintered body, and the described powder of sintering makes it stable borderline phase by cobalt and aluminium and resists corrosion to provide.
9. be used to produce have highly corrosion resistant and have by cobalt and aluminium make it stable borderline phase resist corrosion (Fe Co)-preparation method of the alloy powder of B-R-four directions type permanent magnet, the method is characterized in that to comprise:
The alloy of mainly being made up of following component is provided:
12-14.5 atom % neodymium and 0.2-3.0 atom % dysprosium, the summation of neodymium and dysprosium is 12.5-15 atom %;
6-8 atom % boron;
0.5-8 atom % cobalt;
0.5-3 atom % aluminium;
The content of objectionable impurities carbon is no more than 1000ppm;
Surplus is at least the iron of 68 atom %;
The content that the content of objectionable impurities carbon is no more than 1000ppm and objectionable impurities chlorine in the powder that forms is no more than under the condition of 1500ppm, carry out wet-milling with the alloy grind into powder that forms with solvent, make it stable borderline phase by cobalt and aluminium and resist corrosion to provide.
10. grind and sintering is that chlorinty is no more than under the condition of 1000ppm and carries out in sintered body according to the process of claim 1 wherein.
11. according to the method for claim 2, grind being wherein that in the powder that forms chlorinty is no more than carries out under the condition of 1000ppm.
12., wherein grind and sintering is that nitrogen content is no more than under the condition of 1000ppm and carries out in sintered body according to the method for claim 4.
13. according to the method for claim 5, grind being wherein that in the powder that forms nitrogen content is no more than carries out under the condition of 1000ppm.
14. method is according to Claim 8 wherein ground and sintering is that phosphorus content is no more than under the condition of 700ppm and carries out in sintered body.
15. according to the method for claim 9, grind being wherein that in the powder that forms phosphorus content is no more than carries out under the condition of 700ppm.
16. according to the method for claim 1,4 or 8, wherein sintering is that the ratio of institute's cobalt and aluminium containing total amount and rare earth element is to carry out under the condition of 0.5-10 in the atomic percent borderline phase.
17. according to claim 1, each described method in 2,4,5,8 and 9, wherein alloy also contains the titanium of 0.1-1.0 atom % and niobium or wherein a kind of.
18. according to claim 1,3 or 8 method, wherein sintering is to contain in the sintered body that forms as carrying out under the rich heterogeneous condition of the rare earth of crystal boundary phase, and cobalt, the aluminium that is no more than 5 atom % and the surplus of the rich heterogeneous 5-30 of the containing atom % of described rare earth are mainly rear earth element nd and dysprosium.
19. according to claim 1,2,4,5,8 or 9 method, wherein said alloy provides by fusion.
20. according to claim 1,2,4,5,8 or 9 method, wherein wet-milling is carried out in organochlorine-fluorine compounds solvent.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN 91103569 CN1051864C (en) | 1986-08-04 | 1987-08-04 | Rare earth permanent magnet having excellent corrosion resistance |
Applications Claiming Priority (5)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP182998/86 | 1986-08-04 | ||
| JP61182998A JPH0668144B2 (en) | 1986-08-04 | 1986-08-04 | Rare earth magnet material with excellent corrosion resistance |
| JP182998/1986 | 1986-08-04 | ||
| US90173686A | 1986-08-29 | 1986-08-29 | |
| US901,736 | 1986-08-29 |
Related Child Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN 91103569 Division CN1051864C (en) | 1986-08-04 | 1987-08-04 | Rare earth permanent magnet having excellent corrosion resistance |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN87106209A CN87106209A (en) | 1988-04-27 |
| CN1051865C true CN1051865C (en) | 2000-04-26 |
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ID=26501584
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| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN 87106209 Expired - Lifetime CN1051865C (en) | 1986-08-04 | 1987-08-04 | Rare earih magnet having excellent corrosion resistance |
Country Status (4)
| Country | Link |
|---|---|
| EP (1) | EP0255939B1 (en) |
| CN (1) | CN1051865C (en) |
| CA (1) | CA1336866C (en) |
| DE (1) | DE3786719T2 (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101026034B (en) * | 2006-02-22 | 2010-05-12 | 南京理工大学 | Method for preparing corrosion resistance rare earth permanent-magnetic material |
Families Citing this family (16)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE3740157A1 (en) * | 1987-11-26 | 1989-06-08 | Max Planck Gesellschaft | SINTER MAGNET BASED ON FE-ND-B |
| US5162064A (en) * | 1990-04-10 | 1992-11-10 | Crucible Materials Corporation | Permanent magnet having improved corrosion resistance and method for producing the same |
| JPH04337604A (en) * | 1991-05-14 | 1992-11-25 | Seiko Instr Inc | Rare-earth iron permanent magnet |
| CN1066280C (en) * | 1993-04-16 | 2001-05-23 | 同和矿业株式会社 | Permanent magnet alloy having improved resistance to oxidation |
| DE69716588T2 (en) * | 1996-04-10 | 2003-06-12 | Showa Denko Kk | Cast alloy for the production of permanent magnets with rare earths and process for the production of this alloy and these permanent magnets |
| JP2001332410A (en) * | 2000-05-22 | 2001-11-30 | Seiko Epson Corp | Magnet powder, its manufacturing method, and bond magnet |
| KR100771676B1 (en) | 2000-10-04 | 2007-10-31 | 가부시키가이샤 네오맥스 | Rare earth sintered magnet and method for manufacturing the same |
| WO2006043348A1 (en) | 2004-10-19 | 2006-04-27 | Shin-Etsu Chemical Co., Ltd. | Method for producing rare earth permanent magnet material |
| JP4656323B2 (en) | 2006-04-14 | 2011-03-23 | 信越化学工業株式会社 | Method for producing rare earth permanent magnet material |
| US7955443B2 (en) | 2006-04-14 | 2011-06-07 | Shin-Etsu Chemical Co., Ltd. | Method for preparing rare earth permanent magnet material |
| JP4753030B2 (en) * | 2006-04-14 | 2011-08-17 | 信越化学工業株式会社 | Method for producing rare earth permanent magnet material |
| JP4840606B2 (en) | 2006-11-17 | 2011-12-21 | 信越化学工業株式会社 | Rare earth permanent magnet manufacturing method |
| MY149353A (en) | 2007-03-16 | 2013-08-30 | Shinetsu Chemical Co | Rare earth permanent magnet and its preparations |
| US8105444B2 (en) * | 2007-05-30 | 2012-01-31 | Shin-Etsu Chemical Co., Ltd. | Process for producing highly anticorrosive rare earth permanent magnet and method of using the same |
| JP5303738B2 (en) * | 2010-07-27 | 2013-10-02 | Ｔｄｋ株式会社 | Rare earth sintered magnet |
| CN105599382A (en) * | 2015-12-23 | 2016-05-25 | 常熟市东方特种金属材料厂 | Compound anti-oxidative special metal material |
Family Cites Families (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS6034005A (en) * | 1983-08-04 | 1985-02-21 | Sumitomo Special Metals Co Ltd | Permanent magnet |
| JPS6148904A (en) * | 1984-08-16 | 1986-03-10 | Hitachi Metals Ltd | Manufacture of permanent magnet |
| DE3676403D1 (en) * | 1985-09-10 | 1991-02-07 | Toshiba Kawasaki Kk | PERMANENT MAGNET. |
| JPH07105289B2 (en) * | 1986-03-06 | 1995-11-13 | 信越化学工業株式会社 | Rare earth permanent magnet manufacturing method |
-
1987
- 1987-08-04 CN CN 87106209 patent/CN1051865C/en not_active Expired - Lifetime
- 1987-08-04 EP EP19870111257 patent/EP0255939B1/en not_active Expired - Lifetime
- 1987-08-04 CA CA 543678 patent/CA1336866C/en not_active Expired - Lifetime
- 1987-08-04 DE DE19873786719 patent/DE3786719T2/en not_active Expired - Lifetime
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101026034B (en) * | 2006-02-22 | 2010-05-12 | 南京理工大学 | Method for preparing corrosion resistance rare earth permanent-magnetic material |
Also Published As
| Publication number | Publication date |
|---|---|
| DE3786719T2 (en) | 1993-12-09 |
| EP0255939B1 (en) | 1993-07-28 |
| CA1336866C (en) | 1995-09-05 |
| DE3786719D1 (en) | 1993-09-02 |
| CN87106209A (en) | 1988-04-27 |
| EP0255939A2 (en) | 1988-02-17 |
| EP0255939A3 (en) | 1989-05-31 |
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Assignee: Antai Science and Technology Co., Ltd. Assignor: Sumitomo Special Metals Co., Ltd. Contract fulfillment period: August 4, 2007 Contract record no.: 031000030201 Denomination of invention: Method for producing rare earth permanent magnet with excellent corrosion resistance Granted publication date: 20000426 License type: General permission Record date: 20030702 |
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