CN105612594A - Method for producing a permanent magnet and permanent magnet and electric machine having such a permanent magnet - Google Patents
Method for producing a permanent magnet and permanent magnet and electric machine having such a permanent magnet Download PDFInfo
- Publication number
- CN105612594A CN105612594A CN201480055286.1A CN201480055286A CN105612594A CN 105612594 A CN105612594 A CN 105612594A CN 201480055286 A CN201480055286 A CN 201480055286A CN 105612594 A CN105612594 A CN 105612594A
- Authority
- CN
- China
- Prior art keywords
- particle diameter
- permanent magnet
- magnetic material
- particle
- grinding
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
Classifications
-
- 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
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B22—CASTING; POWDER METALLURGY
- B22F—WORKING METALLIC POWDER; MANUFACTURE OF ARTICLES FROM METALLIC POWDER; MAKING METALLIC POWDER; APPARATUS OR DEVICES SPECIALLY ADAPTED FOR METALLIC POWDER
- B22F1/00—Metallic powder; Treatment of metallic powder, e.g. to facilitate working or to improve properties
- B22F1/05—Metallic powder characterised by the size or surface area of the particles
- B22F1/054—Nanosized particles
- B22F1/056—Submicron particles having a size above 100 nm up to 300 nm
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B22—CASTING; POWDER METALLURGY
- B22F—WORKING METALLIC POWDER; MANUFACTURE OF ARTICLES FROM METALLIC POWDER; MAKING METALLIC POWDER; APPARATUS OR DEVICES SPECIALLY ADAPTED FOR METALLIC POWDER
- B22F5/00—Manufacture of workpieces or articles from metallic powder characterised by the special shape of the product
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B22—CASTING; POWDER METALLURGY
- B22F—WORKING METALLIC POWDER; MANUFACTURE OF ARTICLES FROM METALLIC POWDER; MAKING METALLIC POWDER; APPARATUS OR DEVICES SPECIALLY ADAPTED FOR METALLIC POWDER
- B22F9/00—Making metallic powder or suspensions thereof
- B22F9/02—Making metallic powder or suspensions thereof using physical processes
- B22F9/023—Hydrogen absorption
-
- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C28/00—Alloys based on a metal not provided for in groups C22C5/00 - C22C27/00
-
- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C38/00—Ferrous alloys, e.g. steel alloys
- C22C38/002—Ferrous alloys, e.g. steel alloys containing In, Mg, or other elements not provided for in one single group C22C38/001 - C22C38/60
-
- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C38/00—Ferrous alloys, e.g. steel alloys
- C22C38/005—Ferrous alloys, e.g. steel alloys containing rare earths, i.e. Sc, Y, Lanthanides
-
- 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
- H01F1/0551—Alloys characterised by their composition containing rare earth metals and magnetic transition metals, e.g. SmCo5 in the form of particles, e.g. rapid quenched powders or ribbon flakes
-
- 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
- H01F1/059—Alloys characterised by their composition containing rare earth metals and magnetic transition metals, e.g. SmCo5 and Va elements, e.g. Sm2Fe17N2
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01F—MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
- H01F41/00—Apparatus or processes specially adapted for manufacturing or assembling magnets, inductances or transformers; Apparatus or processes specially adapted for manufacturing materials characterised by their magnetic properties
- H01F41/02—Apparatus or processes specially adapted for manufacturing or assembling magnets, inductances or transformers; Apparatus or processes specially adapted for manufacturing materials characterised by their magnetic properties for manufacturing cores, coils, or magnets
- H01F41/0253—Apparatus or processes specially adapted for manufacturing or assembling magnets, inductances or transformers; Apparatus or processes specially adapted for manufacturing materials characterised by their magnetic properties for manufacturing cores, coils, or magnets for manufacturing permanent magnets
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B22—CASTING; POWDER METALLURGY
- B22F—WORKING METALLIC POWDER; MANUFACTURE OF ARTICLES FROM METALLIC POWDER; MAKING METALLIC POWDER; APPARATUS OR DEVICES SPECIALLY ADAPTED FOR METALLIC POWDER
- B22F9/00—Making metallic powder or suspensions thereof
- B22F9/02—Making metallic powder or suspensions thereof using physical processes
- B22F9/04—Making metallic powder or suspensions thereof using physical processes starting from solid material, e.g. by crushing, grinding or milling
- B22F2009/043—Making metallic powder or suspensions thereof using physical processes starting from solid material, e.g. by crushing, grinding or milling by ball milling
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B22—CASTING; POWDER METALLURGY
- B22F—WORKING METALLIC POWDER; MANUFACTURE OF ARTICLES FROM METALLIC POWDER; MAKING METALLIC POWDER; APPARATUS OR DEVICES SPECIALLY ADAPTED FOR METALLIC POWDER
- B22F2998/00—Supplementary information concerning processes or compositions relating to powder metallurgy
- B22F2998/10—Processes characterised by the sequence of their steps
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B22—CASTING; POWDER METALLURGY
- B22F—WORKING METALLIC POWDER; MANUFACTURE OF ARTICLES FROM METALLIC POWDER; MAKING METALLIC POWDER; APPARATUS OR DEVICES SPECIALLY ADAPTED FOR METALLIC POWDER
- B22F2999/00—Aspects linked to processes or compositions used in powder metallurgy
-
- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C2202/00—Physical properties
- C22C2202/02—Magnetic
Abstract
The invention relates to a method for producing a permanent magnet, wherein a powder of a magnetic material is produced and the powder of the magnetic material is processed into a permanent magnet. According to the invention, the producing of the powder of the magnetic material comprises the steps: grinding a suspension of particles of the magnetic material of a first average particle size in liquid nitrogen, obtaining particles of the magnetic material of a second average particle size, which is smaller than the first average particle size, and separating a suspension of the ground magnetic material in liquid nitrogen, wherein particles having a particle size smaller than a predetermined upper particle size are separated.
Description
The present invention relates to the method for the preparation of permanent magnet, the magnetic of preparing for magnet in particular for preparationThe method of the powder of property raw material. The invention further relates to and use the permanent magnet prepared of the method and compriseThe motor of at least one this permanent magnet.
For example, to the demand of permanent magnet high performance, that use in motor in continuous growth. Especially,Permanent magnet is using for the motor of hauling machine motor-car, and these permanent magnets are increasing at electric automobileProcess in won concern. Mainly apply as magnetic or the magnetizable alloy with high-coercive forceThe rare earth alloy of SE-TM-B or SE-TM type, wherein SE is rare earth element, TM be iron group (Fe, Co,Ni) transition metal, B is boron.
Typical case preparation method comprises following processing step: the powdered of magnetic raw material; Outside using or not usingPortion magnetic field is by powder compaction/be compacted into green compact (Gr ü nteil), to form required structure; Sintering green compact are to enterOne step compression (high-temperature process); Optional temperature adjustment (heating or K cryogenic treatment) is to eliminate stress and so that magnetIn Stability Analysis of Structures; And magnetize in magnetic field. Each processing step is also partly bonded to each other and changesChange order.
The powdered of magnetic raw material generally includes multiple steps. For example, alloy melt is cast into ingot bar (instituteThe ingot of meaning), Mechanical Crushing and stand one or more grinding steps. Known in addition, use band casting(Bandgie β en) technique (English: stripcasting) is processed into alloy melt to have the quick of polycrystalline structureCooling ribbon, subsequently by the further broken and grinding of described ribbon. Also known a kind of hydrogen is quick-fried in additionBroken technique (English HydrogenDecrepitation, HD technique), wherein pressurizes this material with hydrogen, therebyMake hydrogen infiltrate this material from gap and in its dispose procedure subsequently, cause the generation of micro-crack. ByThis can reduce grinding duration subsequently. Different technique with it-so-called HDDR technique (hydrogenation disproportionationDehydrogenation restructuring)-metal hydride of temporary transient formation and dehydrogenation subsequently thereof utilized on the other hand, to changeThe structure phase of kind magnetic material is also improved magnetic performance.
It is also known that in addition, in process of lapping, in rareearth magnetic material, add lubricant, so thatIn magnetization step subsequently, obtain stronger magnetic domain orientation. Therefore, EP1760734A1 has described,Under the existence of lubricant, grind rareearth magnetic material, the particle diameter of this lubricant is greater than the particle diameter of magnetic material.For example, in order to produce required lubricant (stearate) particle diameter, this lubricant is solidified by liquid nitrogen andGrind with freezing state. The particle diameter of the magnet powder obtaining is disclosed as 2.5 to 10 μ m.
By the method for known a kind of rare-earth magnet for the preparation of sintering in DE112010004576T5,Wherein first in single roller or two roller technique by rareearth magnetic material as Nd2Fe14The melt preparation of B is fastThe polycrystalline ribbon of speed cooling (quenching), by this polycrystalline ribbon by cooling procedure on one-sided or twoIn side, form rich Nd phase, this richness Nd has the Nd of ratio mutually2Fe14The fusing point that B is lower. This ribbon is pulverized alsoAnd in the temperature experience low-temperature sintering of the fusing point corresponding to rich Nd phase. Should prevent from being included in thus polycrystallineMutually and meta particle diameter be the alligatoring of 10 to 200nm crystal.
EP0416595A2 has described a kind of preparation method for rare-earth magnet, wherein first makes magneticThe melt through solidifying of material broken and subsequently in the situation that supplying with liquid nitrogen at disc type or impact type powderIn broken machine, grind, wherein form the particle diameter that is up to 400 μ m. Carry out subsequently the hydrogenation of material and in liquid stateIn hydrocarbon, again grind, to obtain the particle diameter that is up to 40 μ m, be generally the particle diameter of 2.7 to 3.5 μ m. Go outIn passivation object, obtained powder is controlled oxidation, moulding, in magnetic field, is orientated, is suppressed alsoSintering.
From US5,609,695 is known, by above-mentioned HD technique, magnetic alloy is ground into and is up to 150 μ mParticle diameter, and in nitrogen atmosphere, this material is added to nitrogen subsequently, for example, by Sm2Fe17Be converted intoSm2Fe17Nx. Subsequently in liquid nitrogen, at the material that adds nitrogen described in grinding in ball grinder, wherein obtain 1 toThe particle diameter of 2 μ m. Determined, because material embrittlement is when liquid nitrogen can reduce required grinding at low temperaturesLong.
US5,382,303 have also described a kind of method for the preparation of magnet, wherein Sm-Co type magnetic materialMaterial is melted, casts and broken and experience corase grind technique in liquid nitrogen next, is up to 600 to obtainThe particle diameter of μ m. Finally refine step, wherein by powder together with liquid hydrocarbon at grinder or ball millingIn machine, be further ground to 40 μ m, especially the maximum particle diameter of 3.8 to 4.6 μ m. Removing dealkylation and passivationAfter powder, it is suppressed in magnetic field and the green compact of acquisition like this are carried out to sintering.
Pulverizing when raw material, desirable is that particle diameter in the magnet of making is as much as possible little in principle,Ideally in the size of magnetic domain, thereby closely knit magnet is made up of single domain particle in the ideal case, real thusExisting extra high magnetic field intensity. In protective gas, use current grinding technique (ball mill, aeropulverizer)Realize the particle diameter of 2 to 5 μ m. For example, can realize 3 to 5 μ m with aeropulverizer (jet mill, jetmills)Particle diameter. Grind duration by prolongation and produced agglomerate, described agglomerate is in ensuing magnet preparation processIn cold weld (kaltverschwei β en) and cause undesirable germination each other. On the other hand, existDuring grinding, use additive to cause the pollution of magnet as lubricant, these additives can adversely affectIts machinery and magnetic behavior.
The technical problem that the present invention will solve is now, provides a kind of method of preparing permanent magnet, whereinObtained there is the magnetic performance of improvement, particularly higher coercive field is strong and the mechanical strength that improvesMagnet.
This technical problem is preparation method, permanent magnet and the electricity of the feature by having independent claimsMachine solves.
In the method according to this invention for the preparation of permanent magnet, prepare the powder of magnetic material and by itBe processed into permanent magnet. By formed powder be processed into permanent magnet generally include moulding, compression, solidify andMagnetization. According to the present invention, the powder of preparing magnetic material comprises the following steps:
The suspension of the particles of magnetic material of-grinding the first meta particle diameter in liquid nitrogen, to obtain than firstThe particles of magnetic material of the second meta particle diameter that meta particle diameter is little, and
-separate the suspension of the magnetic material grinding in liquid nitrogen, wherein sub-argument goes out particle diameter on being scheduled toParticle below limit particle diameter.
Therefore the present invention comprises that the deep cooling type of magnetic material grinds (low-temperature grinding) (kryogenemMahlen) (below also referred to as cryogenic grinding (cryogrinding), KryoMahlen) separates (low-temperature with deep cooling typeSeparate) combination of (below also referred to as cryogenic separation (cryogenic separation), Kryo-Separieren). At these twoIn step, magnetic material is present in liquid nitrogen with form of suspension. (low by the cryogenic grinding in liquid nitrogenTemperature is ground), avoid low temperature (77K) due to liquid nitrogen to cause the heating of abrasive. Thus, avoidedThe reunion of particle and welding have also realized the preparation of low especially particle diameter thus. Therefore the existence of liquid nitrogen allowsExtend and grind duration to realize required very little particle diameter. Ensuing separating step (classification) is at liquid nitrogenIn carry out. Thereby in this separating step, also offset the reunion of particle. Described separation further makes to obtainParticle diameter that must be lower distributes becomes possibility, and the particle that wherein particle diameter is greater than the predetermined particle diameter upper limit is excluded and goesRemove. Distribute and realized in the magnet of making more closely and more uniform spherical accumulation by low particle diameter.Higher magnet mechanical strength and higher magnet coercive field are obtained thus strong.
Separate (also referred to as classification) and be appreciated that as a kind of technique, wherein distribute (conventionally from thering is certain particle diameterCorresponding to Gaussian distribution) granular feedstock in obtain and there is the level distributing than the particle diameter of raw material less (narrower)Divide (Fraktion). In other words, separate and get rid of initial size distribute upper end and/or lower endGrade is divided. Described separation within the scope of the invention comprises that at least one makes to have and is greater than predetermined maximum particle diameterParticle diameter particle fraction separate process, be less than or equal to thereby target fraction finally comprises its particle diameterThe particle of large particle diameter. At this, term " particle diameter " represents so-called equivalent diameter, and it has considered particle oneAs do not there is the fact of accurate spherical structure. For example a kind of particle has nothing to do and just also can in its geometryBe the square hole of the sieve of 1 μ m through the length of side, this particle has the equivalent diameter (" particle diameter ") of 1 μ m.
In the step of cryogenic separation (cryogenic separation), can separate in principle arbitrarily lower limit particle diameter or onLimit particle diameter, for example particle diameter≤4 μ m. But, for preparing permanent magnet, less particle diameter, specialTo be desired at the particle diameter of nanometer range, to obtain better magnetic performance. In reality of the present inventionExecute in mode, isolate such particle in cryogenic separation step, the predetermined maximum particle diameter of this particle is≤ 500nm, especially≤400nm, preferably≤350nm, particularly preferably≤300nm. This exampleAs the sieve that can be 500nm, 400nm, 350nm or 300nm by the corresponding screen size of usePresent. For example, the screening that is 350nm with sieve aperture width from Particle Phase for 100 quality % have≤The particle diameter of 350nm. By being the low particle diameter of 500nm to the maximum, particle has the size in magnetic domain scope,That is to say so-called single domain particle. Particle diameter is limited to domain size to be caused and has extra high coercive fieldStrong permanent magnet.
According to another design of the present invention, in the step of cryogenic grinding, except upper limit particle diameter, also limitDetermined the lower limit particle diameter of separated particle, thereby for example isolate particle size range be > 2 to 4 μ mGrain. One for the preferred design of permanent magnet in, in separating step, isolate particle size range and be> 100nm is to≤500nm, especially > 100nm is to≤400nm, and preferably > 150nm is to≤350Nm, and particularly preferably > 200nm is to the particle of≤300nm. Low particle diameter distributes and also causes particle to existHigh-bulk-density in the permanent magnet of making and the accumulation of ad hoc rules, realize extra high machinery strong thusDegree and high coercive field are strong. Use the presenting of the upper limit particle diameter of definition and the particle fraction of lower limit particle diameter can be withPlain mode is by one after the other using two (or multiple) sieve to carry out. Relative in order for example to separate its particle diameterIn 100 quality % in > 200nm is to the particle fraction of the scope of≤300nm, by screen size be firstThe sieve of 300nm sieves, and wherein > particle of 300nm is retained in sieve above and is separated. SubsequentlyBy through the first sieve, particle diameter is≤fraction of 300nm is 200nm by screen size second sieve intoRow screening, the particle of wherein≤200nm is through the second sieve. The fraction being retained by described sieve only has >200nm is to the particle diameter of the scope of≤300nm.
According to preferred design of the present invention, in separating step, retain, have be greater than predetermined upperThe particle of the particle diameter of limit particle diameter and/or lower limit particle diameter is sent back to previous grinding steps. Thus in fact withoutProcess valuable magnetic material and guaranteed high material productive rate to loss.
The particle diameter obtaining in cryogenic grinding step is by technological parameter, especially by selected grindingDuration can freely be regulated. Preferably be arranged to, at least 50 quality % of the particle obtaining by grinding,Especially at least 70 quality % and particularly preferably at least 80 quality % there is the 500nm of being up to, especiallyBe up to 400nm, be preferably up to 350nm, and be preferably up to the particle diameter of 300nm. This toolHave following advantage, that is, the most material using in separating step has required maximum grain alreadyFootpath and passed through ensuing separating step. Desirable particle diameter but also can be by other grinding ginsengNumber regulates.
In particularly preferred design of the present invention, specify, make to grind so mutual with the step separatingAssociation, to supply with separating step by the suspension of the magnetic material that has experienced grinding steps. In other words, fromIn grinding steps, obtain by the magnetic material through grinding and the suspension that forms of liquid nitrogen without furtherMaterial prepares just to import the device for separating of step. By saving the replacing of liquid medium (liquid nitrogen) or goingRemove, shortened technique duration and reduced material and cost of energy.
Preferably, described cryogenic grinding carries out in ball mill. Provide high surface by the ball of grinderLong-pending, effectively dispel the heat thus, thereby realized the further inhibition to particle agglomeration. But,In scope of the present invention, can use equally other lapping device that wherein can process suspension.
Shown in separate and preferably in vibration screening device, carry out. Vibration screening device comprises at least one waterThe sieve that plain cloth is put, this sieve vibrates around vibrating shaft (ü bereineSchwingachse). Vibration screening deviceBe particularly suitable for processing suspension.
Described separation preferably includes and adopts multiple sieve classifications that are one another in series, described multiple being one another in seriesSieve classification has the sieve of the screen size of successively decreasing. With which, in preposition sieve classification, remove and there is phaseTo the particle of larger particle diameter, and sort out less particle diameter by rearmounted sieve fraction. Use differentMultiple sieve classifications of screen size, use especially in continuous process, can realize screening durationShorten. In vibration screening device, can realize being especially simply one another in series of multiple sieve classifications.
The present invention relates to a kind of prepared according to the methods of the invention permanent magnet that adopts in addition. This permanent magnetFeature is to have the 500nm of being up to, and is up to especially 400nm, is preferably up to the grain of 300nmThe structure of the particles of magnetic material that footpath and defined particle diameter distribute. According to permanent magnet of the present invention thereforeHave high bulk density, high mechanical stability and high coercive field are strong.
Finally, the present invention relates to a kind of motor, it comprises that at least one is according to permanent magnet of the present invention, outstandingIt is multiple such permanent magnets. In special embodiment, this motor is built as motor, itsMiddle permanent magnet is generally a part for rotor, for example, embed in the laminated core structure of rotor or be fixed on its tableOn face.
Other preferred embodiment of the present invention provided remaining, the spy that mentions in the dependent claimsLevy.
Next set forth in an embodiment the present invention by accompanying drawing. Accompanying drawing shows:
Fig. 1 shows the side of the powder for the preparation of magnetic material of first embodiment of the inventionMethod flow process;
Fig. 2 shows the diagram of HD technique;
Fig. 3 shows the processing step of the cryogenic grinding in ball mill;
Fig. 4 shows the processing step of the cryogenic separation in vibration screening device;
Fig. 5 shows the side of the powder for the preparation of magnetic material second embodiment of the inventionMethod flow process, and
Fig. 6 shows the method flow for the preparation of permanent magnet.
Fig. 1 show for visual first embodiment of the invention for the preparation of magnetic materialThe flow chart of method flow of powder.
The raw material of the method is magnetic material (below also referred to as magnetic material), and it has at least one rare earthThe element (Fe, Co, Ni) of element (also referred to as rare earth metal) and at least one iron group. It is particularly related toThe rare earth alloy of SE-TM-A type or SE-TM type, wherein SE is rare earth element, the transition that TM is iron groupMetal (Fe, Co, Ni), and the A III major element that is the periodic table of elements, be in particular boron (B). ExampleAs, use Nd-Fe-B alloy or Sm-Co alloy.
In the step S1 of Fig. 1 first by with casting, the melt of magnetic material being processed into strip. At this,By melt be cast to rotation on cooling roller, wherein make this melt solidify suddenly. The magnetic obtainingThe strip of material has polycrystalline Nano structure. This structure in the left side of Fig. 2 with rare earth alloy Nd2Fe14B doesFor example presents. Visible, the crystal of this alloy is included mutually by rich neodymium alloy, and this richness neodymium alloy communicatesCross alloy quenching and form.
In order further to improve the fragility of raw materialIn the step S2 of the method, adoptThe quick-fried broken technique of known hydrogen (HD technique, hydrogendecrepitation) is processed by band casting and is obtainedMaterial. , Polycrystalline Magnetic Material is exposed in the nitrogen atmosphere in high pressure, wherein hydrogen is by alloy for this reasonMaterial absorbs. For example, Nd-Fe-B type alloy absorbs approximately 2.5% hydrogen. Eliminate subsequently this material institute suddenlyIn pressure, wherein hydrogen spills. This process is clearly visible on the right side of Fig. 2. It is visible especially,Surrounding Nd2Fe14The rich neodymium of B crystal has produced in mutually and has made the quick-fried broken micro-crack of material. It has for example producedIt is the meta particle diameter of 5 to 10 μ m.
Immediately after HD technique, in the step S3 of the method, start according to of the present invention through quick-fried brokenCryogenic grinding that magnetic material carries out. Shown in the ball mill of this cryogenic grinding process in Fig. 3. Ball millingMachine 10 has double-walled container 11, rotatably arranges agitator 12 therein. Inside at container 11 is enteredOne step exists by hard metal as stainless steel or Zr2The ball 13 that O makes. From step S2, have firstMeta particle diameter, join ball mill through quick-fried broken magnetic material with the form of the suspension 20 in liquid nitrogenIn 10 container 11. Liquid nitrogen has the temperature of about 77K.
The rotation of the agitator 12 by ball mill, ball 13 is in motion. Fig. 3 right side shows twoThe enlarged drawing of ball 13, grinds magnetic raw material in the power existing between by two balls 13 between two ballsParticle 21. Therefore produced the particles of magnetic material with the second meta particle diameter, this second meta particle diameter is littleIn the first meta particle diameter of material of supplying with ball mill.
Liquid nitrogen soaks the powder particle 21 of magnetic material and sheds in the heat of this generation during grinding. ByThis, prevented the reunion of particle. Liquid nitrogen makes powder surface avoid polluting and preventing pyrophorisity magnetic in additionMaterial forms and contacts with airborne oxygen.
Grinding technics preferably carries out the long like this time, until at least 90 quality of dusty material-% toolBe up to 500nm, be preferably up to the particle diameter of 300nm. So select processing parameter, withObtain required particle diameter. These processing parameters depend on used equipment and equipment size. For example,The rotating speed of agitator be adjusted to 150 to 1000U/min and grind duration be adjusted to 1 to 12 hour.
According to Fig. 1, in step S4, immediately cryogenic grinding carries out cryogenic separation (classification). This process is at Fig. 4Shown in.
Shown here separator 30 has double-walled housing 31, and this double-walled housing is fed by cryogenic grindingThe suspension 20 obtaining, formed by powder and the liquid nitrogen of magnetic material. Flatly upper and lower in housing 31Arrange stackedly multiple vibratory sieves 33. At this, the screen size from top to down of sieve 33 successively decreases. Sieve 33 withVertical vibrating axis 32 mechanical connections. Vibration axis 32 is located at vertical vibrating by unshowned driverIn, this vertical vibrating and then be transferred to vibratory sieve 33. For example can use the woven wire with sinteringSieve. What be applicable to equally is so-called MEMS sieve (the microelectron-mechanical knot of preparing by wet or dry etching processStructure, micro-electro-mechanical-structure).
First powder with the magnetic material of the form supply of suspension 20 arrives uppermost, the thickest sieveUpper, be greater than the corresponding screen size of this sieve, the particle that is for example greater than 500nm is retained on described sieve.The particle of particle diameter≤500nm arrives the next sieve of arranging thereunder, and this sieve has and is slightly less than topmostThe screen size of sieve, for example there is the screen size of 400nm. Thereby retain on the second sieve 400Nm is to the particle of≤500nm. This process proceeds until the sieve of below, and this sieve defines requiredMaximum particle diameter, for example 300nm.
Thus, by valve 34 discharge and collect after filtration with separate, only still comprise preferably≤300nmThe suspension 20 of particle diameter. The fraction being retained on sieve 33 is returned to previous cryogenic grinding processing stepS3. Cooling step optionally can be set betwixt.
Between the separation period of step S4, produced frictional heat is removed by liquid nitrogen, prevent thus magneticThe reunion of particle. The use of the form of the suspension in liquid nitrogen has realized in addition, can be without in mediumDisconnected ground (Medienbruch) is sent the particle fraction being retained on sieve 33 in the step of cryogenic grinding back to.
Fig. 5 shows the procedure for the preparation of Magnaglo second embodiment of the inventionFlow chart. The difference of the method shown in the method and Fig. 1 is only two first steps, and according to thisThe step S3 of invention and S4 are identical and do not set forth again and again.
According to Fig. 5, in first step S1', first alloy melt be cast into little ingot bar (ingot) and makeIt solidifies. Mechanically make subsequently these little ingot bars broken in protection gas, wherein produce metaParticle diameter is for example the particle of 500 μ m.
In following step S2' by conventional in protective atmosphere, for example, at gaseous nitrogen atmosphere or argonGrinding in gas realizes the further mechanical crushing to material. Corase grind step S2' can be for example at aeropulverizerIn (jet mill), also or in ball mill carry out. The particle diameter obtaining is for example 3 to 5 μ m. This is explainingIn the step S3 stating and S4, further pulverized, to obtain the particle diameter that is preferably up to 300nm.
Fig. 6 exemplarily shows other method flow, wherein in step S4 (from Fig. 1 or 5), obtainsThe powder obtaining is further processed into permanent magnet.
In step S5, carry out compression and the moulding of the powder of magnetic material by compacting. This compacting can be non-Carry out in mechanical press (pressurizing tool) Deng static pressure ground (anisostatisch), wherein by mechanical pressure from oneIndividual or two relative direction in spaces are applied on casting die. Alternatively, this compacting can wait static pressure and leads toCross to powder and load and realize with the high pressure of protective atmosphere. Compacting all can be in outside in both casesIn magnetic field, carry out, thus the casting die of generation magnetic anisotropy. The result of compression step S5 is that (magnetic is respectively to sameProperty or magnetic anisotropy) casting die, this casting die is also referred to as green compact.
In following step S6, carry out the sintering of green compact. At this, green compact are less than or equal to magneticAt the temperature of the fusing point of material, solidify. For example, for NdFeB type as Nd2Fe14Type B alloy, uses modelBe trapped among the temperature of 1000 to 1150 DEG C. By sintering process, powder particle is further compressed and solidified alsoAnd forming mechanical type and connect, is also partly that material engagement type connects. After sintering, exist unmagnetized body (eachTo the same sex or anisotropic, depend on and noly in magnetic field, suppress) because obtained residence during sinteringIn remaining (Curie-bleibt).
In following step S7, then carry out optional tempering process, wherein magnet experience furtherHeat treatment (K cryogenic treatment). The object of this temperature adjustment is the residual stress of eliminating in crystal structure.
In another optional step S8, carry out processing and forming and/or the surface treatment of magnet, to giveThe shape and size that need. Particularly can use Machining Technology as grinding, cutting, milling etc. ButPreferably, the net shape of magnet is established in compression step S5, for example, (pass through) corresponding pressing moldSet up, thereby save machining or can at least reduce described machining. In addition, this magnet can be establishedThere is face coat, the face coat for example being formed by epoxy resin or metal coating
Finally in step S9, carry out the magnetization of magnet in external magnetic field, wherein make magnetic dipole(magnetischenDipole) magnetization, that is to say and make magnetic dipole orientation.
Use the method according to this invention prepared permanent magnet to be characterised in that low at the magnetic domain order of magnitudeParticle diameter, that is, it is made up of so-called single domain particle. In addition, this permanent magnet has uniform particle diameter and distributes,This particle diameter distributes preferably in 200 to 300nm scope. Result is that this magnet is characterised in that high rectifyingStupid field intensity and high temperature stability. Its good magnetic spy can be not because of the content of rare earth raising impaired,Described rare earth for example with the form of Dy or Tb, for example, by procedure of processing (crystal boundary conventional in prior artDiffusion process, GBDP, grainboundarydiffusionprocess) introduce. Due to real in liquid nitrogenExecute responsive powder procedure of processing, thereby also reduced other impurity with carbon or oxygen form. Interference is doneWith as the formation of recrystallization, thermal stress and aggregate, in cryogenic grinding, eliminated. The spy of the methodLevy and be also high security, because liquid nitrogen has suppressed the spontaneous combustion tendency of magnet powder.
Reference numeral list
10 ball mills
11 containers
12 agitators
13 balls
20 suspension
21 particles
30 separators
31 housings
32 vibration axis
33 vibratory sieves
34 valves
Claims (10)
1. for the preparation of a method for permanent magnet, wherein prepare the powder of magnetic material and by this magneticThe powder of property material is processed into permanent magnet, it is characterized in that, the preparation of the powder of described magnetic material comprisesFollowing steps:
The suspension of the particles of magnetic material of-grinding the first meta particle diameter in liquid nitrogen, to obtain than firstThe particles of magnetic material of the second meta particle diameter that meta particle diameter is little, and
-separate the suspension of the magnetic material grinding in liquid nitrogen, wherein isolate particle diameter on being scheduled toParticle below limit particle diameter.
2. method according to claim 1, is characterized in that, isolates grain in separating stepFootpath is≤500nm, especially≤400nm, preferably≤350nm, particularly preferably≤300nm'sParticle.
3. according to the method one of aforementioned claim Suo Shu, it is characterized in that, in separating step, divideFrom go out particle size range for > 100nm is to≤500nm, especially > 100nm is to≤400nm, preferably> 150nm is to≤350nm, and particularly preferably > 200nm is to the particle of≤300nm.
4. according to the method one of aforementioned claim Suo Shu, it is characterized in that, in the future self-separation step, the particle of particle diameter more than predetermined upper limit particle diameter return to grinding steps.
5. according to the method one of aforementioned claim Suo Shu, it is characterized in that, make to grind and separate stepSuddenly so interrelated, so that the suspension of the magnetic material that has experienced grinding steps is supplied with to separating step.
6. according to the method one of aforementioned claim Suo Shu, it is characterized in that, described grinding is at ball millingIn machine, carry out.
7. according to the method one of aforementioned claim Suo Shu, it is characterized in that, described separation is by shakingMoving screening plant carries out.
8. according to the method one of aforementioned claim Suo Shu, it is characterized in that, described separation comprises to be madeWith multiple sieve classifications that are one another in series, described multiple sieve classifications that are one another in series use the sieve aperture chi successively decreasingVery little.
9. a permanent magnet, it is by preparing according to the method one of claim 1 to 8 Suo Shu.
10. a motor, comprises at least one permanent magnet according to claim 9.
Applications Claiming Priority (3)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| DE102013220452.3 | 2013-10-10 | ||
| DE201310220452 DE102013220452A1 (en) | 2013-10-10 | 2013-10-10 | Method for producing a permanent magnet and permanent magnet and electric machine with such a permanent magnet |
| PCT/EP2014/070047 WO2015051986A1 (en) | 2013-10-10 | 2014-09-19 | Method for producing a permanent magnet and permanent magnet and electric machine having such a permanent magnet |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN105612594A true CN105612594A (en) | 2016-05-25 |
| CN105612594B CN105612594B (en) | 2018-11-23 |
Family
ID=51627264
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201480055286.1A Active CN105612594B (en) | 2013-10-10 | 2014-09-19 | It is used to prepare the method and permanent magnet and the motor with permanent magnet of permanent magnet |
Country Status (5)
| Country | Link |
|---|---|
| EP (1) | EP3055870B1 (en) |
| KR (1) | KR20160070788A (en) |
| CN (1) | CN105612594B (en) |
| DE (1) | DE102013220452A1 (en) |
| WO (1) | WO2015051986A1 (en) |
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN109473271A (en) * | 2018-11-08 | 2019-03-15 | 浙江嘉兴南湖电子器材集团有限公司 | A kind of magnet orientation compression moulding technique |
| CN110090965A (en) * | 2019-06-10 | 2019-08-06 | 重庆理工大学 | Preparation of high coercive force superfine Sm2Co17Method for producing magnetic powder |
| CN111640566A (en) * | 2020-05-20 | 2020-09-08 | 杭州三炻磁性材料有限公司 | Process method for pressing constant-pressure constant-magnetism samarium cobalt powder |
| CN113546745A (en) * | 2021-06-22 | 2021-10-26 | 国家能源集团宁夏煤业有限责任公司 | Cryogenic crushing device and cryogenic crushing method for preparing polymer powder |
Families Citing this family (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US11145445B2 (en) * | 2016-12-14 | 2021-10-12 | United States Of America As Represented By The Secretary Of The Air Force | Bulk anisotropic exchange-spring magnets and method of producing the same |
| DE102018112411A1 (en) | 2018-05-24 | 2019-11-28 | Netzsch Trockenmahltechnik Gmbh | Process and plant for the production of a starting material for the production of rare earth magnets |
Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP0350781A2 (en) * | 1988-07-12 | 1990-01-17 | Idemitsu Kosan Company Limited | Magnetic powder material and resin-bonded type magnet |
| EP0416595A2 (en) * | 1989-09-06 | 1991-03-13 | SPS TECHNOLOGIES, Inc. | Process for making Nd-Fe-B type magnets utilizing a hydrogen and oxygen treatment |
| US5382303A (en) * | 1992-04-13 | 1995-01-17 | Sps Technologies, Inc. | Permanent magnets and methods for their fabrication |
| US5609695A (en) * | 1993-12-21 | 1997-03-11 | Matsushita Electric Industrial Co., Ltd. | Method for producing alloy powder of the R2 T17 system, a method for producing magnetic powder of the R2 T17 Nx system, and a high pressure heat-treatment apparatus |
| CN1479326A (en) * | 2003-07-21 | 2004-03-03 | 北京科技大学 | Method of preparing samarium iron nitrogen permanent amgnet material using mechanical alloying |
| CN102047536A (en) * | 2008-05-30 | 2011-05-04 | 株式会社东芝 | Permanent magnet and manufacturing method therefor, permanent magnet for motor and permanent magnet motor |
Family Cites Families (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CA845703A (en) * | 1970-02-13 | 1970-06-30 | International Bronze Powders Limited | Pigment classification |
| BR0200152A (en) * | 2002-01-22 | 2003-10-21 | Ivan Calia Barchese | Process for obtaining an iron - aluminum pre - alloy tablet produced from atomized powders for use as an alloying element in aluminum and tablet obtained by the process |
| EP1760734A1 (en) | 2004-06-25 | 2007-03-07 | TDK Corporation | Rare earth sintered magnet, raw material alloy powder for rare earth sintered magnet, and process for producing rare earth sintered magnet |
| US20100054981A1 (en) * | 2007-12-21 | 2010-03-04 | Board Of Regents, The University Of Texas System | Magnetic nanoparticles, bulk nanocomposite magnets, and production thereof |
| JP5093215B2 (en) | 2009-11-26 | 2012-12-12 | トヨタ自動車株式会社 | Method for producing sintered rare earth magnet |
| WO2013010173A1 (en) * | 2011-07-14 | 2013-01-17 | Northeastern University | Rare earth-free permanent magnetic material |
-
2013
- 2013-10-10 DE DE201310220452 patent/DE102013220452A1/en not_active Withdrawn
-
2014
- 2014-09-19 EP EP14777023.4A patent/EP3055870B1/en active Active
- 2014-09-19 KR KR1020167012176A patent/KR20160070788A/en active Search and Examination
- 2014-09-19 CN CN201480055286.1A patent/CN105612594B/en active Active
- 2014-09-19 WO PCT/EP2014/070047 patent/WO2015051986A1/en active Application Filing
Patent Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP0350781A2 (en) * | 1988-07-12 | 1990-01-17 | Idemitsu Kosan Company Limited | Magnetic powder material and resin-bonded type magnet |
| EP0416595A2 (en) * | 1989-09-06 | 1991-03-13 | SPS TECHNOLOGIES, Inc. | Process for making Nd-Fe-B type magnets utilizing a hydrogen and oxygen treatment |
| US5382303A (en) * | 1992-04-13 | 1995-01-17 | Sps Technologies, Inc. | Permanent magnets and methods for their fabrication |
| US5609695A (en) * | 1993-12-21 | 1997-03-11 | Matsushita Electric Industrial Co., Ltd. | Method for producing alloy powder of the R2 T17 system, a method for producing magnetic powder of the R2 T17 Nx system, and a high pressure heat-treatment apparatus |
| CN1479326A (en) * | 2003-07-21 | 2004-03-03 | 北京科技大学 | Method of preparing samarium iron nitrogen permanent amgnet material using mechanical alloying |
| CN102047536A (en) * | 2008-05-30 | 2011-05-04 | 株式会社东芝 | Permanent magnet and manufacturing method therefor, permanent magnet for motor and permanent magnet motor |
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN109473271A (en) * | 2018-11-08 | 2019-03-15 | 浙江嘉兴南湖电子器材集团有限公司 | A kind of magnet orientation compression moulding technique |
| CN110090965A (en) * | 2019-06-10 | 2019-08-06 | 重庆理工大学 | Preparation of high coercive force superfine Sm2Co17Method for producing magnetic powder |
| CN110090965B (en) * | 2019-06-10 | 2022-05-13 | 重庆理工大学 | Preparation of high coercive force superfine Sm2Co17Method for producing magnetic powder |
| CN111640566A (en) * | 2020-05-20 | 2020-09-08 | 杭州三炻磁性材料有限公司 | Process method for pressing constant-pressure constant-magnetism samarium cobalt powder |
| CN113546745A (en) * | 2021-06-22 | 2021-10-26 | 国家能源集团宁夏煤业有限责任公司 | Cryogenic crushing device and cryogenic crushing method for preparing polymer powder |
Also Published As
| Publication number | Publication date |
|---|---|
| EP3055870A1 (en) | 2016-08-17 |
| EP3055870B1 (en) | 2019-11-13 |
| KR20160070788A (en) | 2016-06-20 |
| CN105612594B (en) | 2018-11-23 |
| WO2015051986A1 (en) | 2015-04-16 |
| DE102013220452A1 (en) | 2015-04-30 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN105612594A (en) | Method for producing a permanent magnet and permanent magnet and electric machine having such a permanent magnet | |
| JP6177877B2 (en) | Method for manufacturing RFeB-based sintered magnet and RFeB-based sintered magnet manufactured thereby | |
| US9734947B2 (en) | Rare earth sintered magnet and making method | |
| CN102816991B (en) | Low-temperature nitridation preparation method of iron-based rare earth permanent magnet powder | |
| CN104272403B (en) | R-T-B system permanent magnet | |
| WO2013027592A1 (en) | Method for producing powder compact for magnet, powder compact for magnet, and sintered body | |
| US7045092B2 (en) | Method for press molding rare earth alloy powder and method for producing sintered object of rare earth alloy | |
| Zhihua et al. | Enhanced magnetic properties in Nd-Fe-B magnets prepared by spark plasma sintering via die-upsetting process | |
| KR102215818B1 (en) | Hot-deformed magnet comprising nonmagnetic alloys and fabricating method thereof | |
| JP2003226944A (en) | Sintered magnet using rare earth-iron-boron alloy powder for magnet | |
| CN106816249A (en) | A kind of preparation method of the nanocrystalline permanent magnet of cheap light rare earth lanthanum ferrocerium boron | |
| JP2859517B2 (en) | Rare earth magnet manufacturing method | |
| US11309127B2 (en) | Method and plant for the production of a starting material for the production of rare earth magnets | |
| JP2015026795A (en) | Powder for magnets, rare earth magnet, method for manufacturing powder for magnets, and method for manufacturing rare earth magnet | |
| JP6471594B2 (en) | Rare earth magnet material and method for producing rare earth magnet material | |
| JP2015007275A (en) | Method of producing powder for magnet, powder for magnet, molding for magnet, magnetic member, and compressed powder magnet | |
| JP4483630B2 (en) | Manufacturing method of rare earth sintered magnet | |
| JP3240034B2 (en) | Rare earth sintered magnet and manufacturing method thereof | |
| JPH1197223A (en) | R-fe-b sintered permanent magnet | |
| Renquan et al. | Effect of crushing methods on morphology and magnetic properties of anisotropic NdFeB powders | |
| Lee et al. | Effect of Deformation on the Magnetic Domain Orientation of Rapidly Solidified Nd–Fe–B Powders Using Pulsed Current Assisted Sintering | |
| JP6447804B2 (en) | Method for manufacturing magnet compact | |
| JP2017216298A (en) | Rare earth magnet material and method for manufacturing rare earth magnet material | |
| EP0443647A1 (en) | Hot-worked rare earth-iron-carbon magnets | |
| Durrant | The effect of microstructure and composition on HDDR processing of scrap magnets |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C06 | Publication | ||
| PB01 | Publication | ||
| C10 | Entry into substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |