EP0633581A1 - Matériaux R-Fe-B pour aimants permanents et leurs procédé de fabrication - Google Patents

Matériaux R-Fe-B pour aimants permanents et leurs procédé de fabrication Download PDF

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EP0633581A1
EP0633581A1 EP93308184A EP93308184A EP0633581A1 EP 0633581 A1 EP0633581 A1 EP 0633581A1 EP 93308184 A EP93308184 A EP 93308184A EP 93308184 A EP93308184 A EP 93308184A EP 0633581 A1 EP0633581 A1 EP 0633581A1
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atomic
permanent magnet
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magnet materials
accordance
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EP0633581B1 (fr
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Yuji Kaneko
Naoyuki Ishigaki
Koki Tokuhara
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Proterial Ltd
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Sumitomo Special Metals Co Ltd
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Priority claimed from JP19288693A external-priority patent/JP3415208B2/ja
Priority claimed from JP20719093A external-priority patent/JP3151087B2/ja
Priority claimed from JP20719193A external-priority patent/JP3151088B2/ja
Priority claimed from JP5207192A external-priority patent/JPH0745412A/ja
Priority claimed from JP21217193A external-priority patent/JP3299000B2/ja
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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
    • 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
    • H01F1/0573—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 obtained by reduction or by hydrogen decrepitation or embrittlement
    • 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
    • B22F3/00—Manufacture of workpieces or articles from metallic powder characterised by the manner of compacting or sintering; Apparatus specially adapted therefor ; Presses and furnaces
    • B22F3/02—Compacting only
    • 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
    • B22F3/00—Manufacture of workpieces or articles from metallic powder characterised by the manner of compacting or sintering; Apparatus specially adapted therefor ; Presses and furnaces
    • B22F3/02—Compacting only
    • B22F3/04—Compacting only by applying fluid pressure, e.g. by cold isostatic pressing [CIP]
    • 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
    • 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
    • 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
    • B22F2202/00—Treatment under specific physical conditions
    • B22F2202/05—Use of magnetic field
    • 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

Definitions

  • the present invention relates to permanent magnet materials composed mainly of R (where, R contains, at least, one kind of rare earth elements containing Y), Fe and B, and a process of producing the same, particularly, it relates to R-Fe-B permanent magnets materials and a process of producing the same, whereby a cast alloy having a homogeneous structure in which an R2Fe14B phase and an R-rich phase are finely separated, or an adjusting alloy cast piece containing a main-phase alloy containing the R2Fe14B phase as a main phase, and an R2Fe17 phase or an R-Co intermetallic compound phase are obtained, from a molten alloy whose main components are R, Fe and B, by a strip casting process such as a single roll process or a double roll process and the like, the cast alloy are subjected to spontaneous decay by utilizing a Hydrogenation of the alloy, and further, subjected to dehydrogenation for stabilization so as to enable the efficient pulverisation, by molding and sintering
  • an R-Fe-B permanent magnet Japanese Patent Application Laid Open No. Sho 59-46008
  • Japanese Patent Application Laid Open No. Sho 59-46008 Japanese Patent Application Laid Open No. Sho 59-46008
  • a high magnetic characteristic is obtained by the structure having a main phase of ternary tetragonal compounds and an R-rich phase, and is used in a broad field from general domestic electric appliance to peripheral equipments of large-sized computers, thus the R-Fe-B permanent magnet having various structure is proposed so as to exhibit various magnetic characteristics depending on uses.
  • a residual magnetic flux density (Br) of an R-Fe-B sintered magnet can be expressed as the following Equation (1).
  • the item 3 usually in a process of producing the R-Fe-B permanent magnet, in order to make the direction of easy magnetization axies of the main phase crystal grains uniform, a process of press molding in the magnetic field is adopted.
  • a residual magnetic flux density (Br) value and a value of the squareness of demagnetization curve ⁇ (Br2/4(BH)max ⁇ change depending on a magnetic field applying direction and a pressing direction, or are influenced by the applied magnetic field intensity.
  • Enhancement of the residual magnetic flux density (Br) of the R-Fe-B sintered magnet can be achieved by increasing a content of the R2Fe14B phase of the main phase which is the Ferro magnetic phase. That is, it is important to make the magnet composition close to the stoichiometric composition of R2Fe14B.
  • the alloy powder having the aforementioned composition when producing the alloy powder having the aforementioned composition by a direct reducing and diffusing process, un-reacted Fe grains, and when raising the reduction temperature to eliminate this, then the grains are growth by Sintered one another, besides Ca added as a reducing agent and its oxides are taken in, thereby to increase impurities.
  • the R-Fe-B sintered magnet is sintered by a liquid-phase sintering reaction. That is, in the magnet, besides the R2Fe14B phase which is the main phase and Ferro magnetic phase, the B-rich phase and R-rich phase as the grain boundary phase are present, which reacts one another at sintering to generate the liquid phase, thereby a densification reaction proceeds.
  • the B-rich phase and the R-rich phase are indispensable phases for producing the R-Fe-B sintered magnet.
  • the R2Fe14B phase which is the main phase and Ferro magnetic phase to the utmost, and for this purpose, it is intensive how to densify the alloy powder which is close to the stoichiometric composition of the R2Fe14B phase.
  • the present invention is that, by the Hydrogenation of the strip casted R-Fe-B alloy having a specific composition and thickness, the R-rich phase which is finely dispersed produces hydrides to cause volume expansion and eventual spontaneous decay of the alloy, thereafter the main phase crystal grains constituting the alloy can be pulverized and the powder having a uniform grain distribution can be produced, at this time, the R-rich phase is finely dispersed and the R2Fe14B phase is also pulverized, thus when the alloy powder which is dehydrogenated and stabilized is pulverized, since a pulverizing powder is improved by about twice as much as the conventional pulverizing efficiency, the production efficiency is largely improved, and by orientation using the pulse magnetic field and pressing, the R-Fe-B permanent magnet, in which Br, BH(max) and iHc are improved remarkably, and the squareness of demagnetization curve shows a value of 1.01 to 1.045, which is brought close to a theoretical state as much as possible, can be obtained.
  • the present invention is that, by adding and blending adjusting alloy powder containing a Nd2Fe17 phase obtained by the strip casting process by 60% or less of the total amount, to the R-Fe-B alloy powder containing the R2Fe14B phase as the main phase obtained by the strip casting process, due to the reaction between the Nd2Fe17 phase in the adjusting alloy powder and the B-rich and Nd-rich phase in the main phase of R-Fe-B alloy powder, a B-rich phase and Nd-rich phase which deteriorate the permanent magnetic characteristics can be adjusted and decreased, the resulting magnet performance can be improved, and further, the oxygen content in the alloy powder can be reduced, thereby the alloy powder having the composition responsive to various magnetic characteristics is provided easily.
  • the present invention is that, by adding and blending the adjusting alloy powder containing an R-Co intermetallic compound phase obtained by the strip casting process by 60% or less of the total amount, to the R-Fe-B alloy powder containing the R2Fe14B phase as the main phase obtained by the strip casting process, even when the liquid-phase sintering can not be effected only by the main phase of R-Fe-B alloy powder due to the shortage of the R-rich phase and B-rich phase, the R-Co intermetallic compound phase of the adjusting alloy powder is melted to supply the liquid phase for high densification, thus the resulting magnet performance can be improved, and further, the oxygen content in the alloy powder can be decreased and the alloy powder having the composition responsive to various magnetic characteristics is provided easily.
  • Fig. 1 is an explanatory view of a press machine, in which a pulse magnetic field and a usual static magnetic field can be acted in common.
  • Fig. 2 is a graph showing the relationship between the time and a magnetic field intensity of a pulse magnetic field.
  • the R-rich phase is finely dispersed and the R2Fe14B phase is fine.
  • the alloy composition is brought close to the stoichiometric composition of the R2Fe14B phase, crystallization of a Fe primary crystal is un avoidable, causing a large deterioration of the pulverizing efficiency in the following process.
  • means for providing the heat treatment and eliminating ⁇ -Fe is taken to homogenize the alloy ingot, since the main phase crystal grains become coarse and segregation of the R-rich phase proceeds, iHc of the sintered magnet is difficult to be improved.
  • a Nd2Fe17 phase in an R-Fe alloy such as a Nd-Fe alloy is an intermetallic compound having a easily magnetizing direction in a C phase when a Curie point is in the vicinity of room temperature, and conventionally, in the R-Fe-B sintered permanent magnet, when the amount of B is less than 6 atomic %, for example, the Nd2Fe17 phase is produced in the magnet to weaken a coercive force.
  • the adjusting alloy powder containing the Nd2Fe17 phase and the R-Fe-B alloy powder containing the R2Fe14B phase as the main phase react as follows during the sintering, and act to increase the R2Fe14B phase as the main phase.
  • the R-Fe-B permanent magnet material powders are obtained, by mixing a necessary amount of main phase alloy powder-and adjusting alloy powder obtained by rapid cooling and solidifying the molten alloy by the strip casting process, to the main phase alloy powder containing the R2Fe14B phase as the main phase and the adjusting alloy powder containing the R2Fe17 phase.
  • reasons for producing the main phase alloy powder and adjusting alloy powder from the alloy obtained by the strip casting process in the present invention are that, by the strip casting, in the main phase alloy powder, the main phase alloy powder can be obtained from the alloy cast piece in which the R2Fe14B main phase in fine and the B-rich phase and Nd-rich phase are sufficiently dispersed, besides, crystallization of Fe primary crystals is suppressed, and in the adjusting alloy powder, which can be obtained from the alloy cast piece in which the R2Fe17 phase is dispersed uniformly.
  • the R2Fe14B phase is fine and the B-rich phase and R-rich phase are uniformly dispersed in the main phase material powders, a pulverizing power is improved considerably at the time of producing the magnet, and the powder having uniform particle distributions can be obtained. Furthermore, when producing the magnet, since the crystal is fine, a high coercive force is obtained.
  • an advantage of producing the adjusting alloy powder containing the R2Fe17 phase by the strip casting process is that, since the R2Fe17 phase can be made fine and dispersed sufficiently at the time of mixing with the main phase alloy powder, the reaction takes place uniformly. That is, in the usual alloy melting process using a mold, since ⁇ -Fe and the other R-Fe (Co) compound phase are crystallized on the resulting alloy ingot, for obtaining the stable material alloy powders, the alloy ingot must be heated and homogenized, causing the production cost of the alloy powder to increase and the R2Fe17 phase to growth. Furthermore, in the case of producing the adjusting alloy powder by a direct reducing and diffusing process, such problems are encountered that, un-reacted Fe grains remain or individual grain compositions differ from each other, and it is very difficult to homogenize the whole alloy powders.
  • the alloy powder made close to the stoichiometric composition of the R2Fe14B phase can be liquid-phase sintered, thereby the magnet composition can be made close to the stoichiometric composition of the R2Fe14B phase.
  • the Nd-rich phase serving as a supply source of the liquid phase produces Nd-oxides during the process by indispensable material oxidation, thereby the amount of liquid phase necessary for sintering can not be secured, as a result, a high densification can not be achieved sufficiently, so that the composition must be set in advance with some margins, but the deviations can be solved by the present invention.
  • the pulverizing power is considerably improved at the time of producing the magnet, and the powder having the uniform grain distributions can be produced. Furthermore, since the crystal is fine, a high coercive force can be obtained when producing the magnet. Particularly, even when the alloy powder composition is made close to the stoichiometric composition of the R2Fe14B phase, crystallization of the Fe primary crystal is eliminated and the uniform structure is obtained.
  • advantages of producing the adjusting alloy powder containing the R-Co intermetallic compound phase by the strip casting process are that, such problems as that, in the usual alloy melting process using the mold, the Co(Fe) phase and the other R-Co(Fe) compound phase are crystallized on the resulting alloy ingot, and the phases omnipresent locally, therefore, in order to obtain the stable material alloy powders, the alloy ingot must be heated and homogenized, causing increase in the production cost of the alloy powder, and that, in the case of producing the adjusting alloy powder by the direct reducing and diffusing process, un-reacted Co and Fe grains remain or individual grain composition differs from each other, thus it is very difficult to homogenize that whole alloy powders, can be solved.
  • Magnetic characteristics of the R-Fe-B permanent magnet according to the present invention is that, a total value A + B of 59 or more, in which A is a maximum energy product value (BH) max; (MGOe) and B is a coercive force iHc(kOe), when (BH) max is above 50 MGOe, iHc is more than 9 kOe, when (BH) max is above 45 MGOe, iHc is more than 14 kOe, and the squareness of demagnetization curve ⁇ (Br2/4(BH) max ⁇ value is 1.01 to 1.045, thus by selecting the composition and production conditions suitably, the necessary magnetic characteristics can be obtained.
  • A is a maximum energy product value (BH) max; (MGOe) and B is a coercive force iHc(kOe)
  • the cast piece of the magnet materials having a structure, in which the R2Fe14B phase having a specific composition and the R-rich phase are finely separated is produced by strip casting the molten alloy having a specific composition by a single roll process or a double roll process.
  • the resulting cast piece is a sheet whose thickness is 0.03 mm to 10 mm, though the single roll process and the double roll process are used properly depending on the desired thickness of the cast piece, the double roll process is preferably adopted when the plate thickness is thick, and the single roll process is preferably used when the plate thickness is thin.
  • a sectional structure of the R-Fe-B alloy having a specific composition obtained by the strip casting process is that, the main phase R2Fe14B crystal is finer than about one tenth or more as compared with that of the conventional ingot obtained by casting in a mold, for example, crystal sizes are 0.1 ⁇ m to 50 ⁇ m in a short axial direction and 5 ⁇ m to 200 ⁇ m in a long axial direction, and the R-rich phase is finely dispersed as surrounding the main phase crystal grain, even in the locally omnipresent region, the size is below 20 ⁇ m. Crystal grains of the main phase alloy powder and the adjusting alloy powder obtained by the strip casting process have the same properties.
  • Rare earth elements R contained in the permanent magnet alloy ingot of the present invention contain yttrium (Y), and are the rare earth elements including light rare earths and heavy rare earths.
  • the light rare earths are sufficient, and particularly, Nd and Pr are preferable.
  • one kind of R is sufficient, practically, mixtures (mischmetal, didymium, etc.) of two kinds or more can be used from the reason of availability, and Sm, Y, La, Ce, Gd etc. can be used as a mixture with other R, particularly, Nd, Pr and the like.
  • the R is not necessarily be the pure rare earth elements, those containing unavoidable impurities in production may be used within an industrially available range.
  • R is an indispensable element of the alloy ingot for producing the R-Fe-B permanent magnet, whereby a high magnetic characteristics can not be obtained below 12 atomic %, particularly, a high coercive force can not be obtained, and when exceeding 16 atomic %, a residual magnetic flux density (Br) is lowered and the permanent magnet having a superb characteristics can not be obtained.
  • the R is preferably within the range of 12 atomic % to 16 atomic %, the optimum range being 12.5 atomic % to 14 atomic %.
  • the B is an indispensable element of the alloy ingot for producing the R-Fe-B permanent magnet, whereby the high coercive force (iHc) can no be obtained below 4 atomic %, and when exceeding 8 atomic %, the residual magnetic flux density (Br) is lowered, so that the good permanent magnet can not be obtained.
  • the B is preferably 4 atomic % to 8 atomic %, the optimum range being 5.8 atomic % to 7 atomic %.
  • the residual magnetic flux density (Br) is lowered below 76 atomic %, and when exceeding 84 atomic %, the high coercive force can not be obtained, so that Fe is restricted to 76 to 84 atomic %.
  • the starting material powders in the present invention besides the material powders of the magnet composition, for adjusting the amount of R, B and Fe to the magnet composition, it is also possible to use by blending the R-Fe-B alloy powder, containing the R2Fe14B phase in which the amount of R, to be described later, is contained by 11 atomic % to 20 atomic % as the main phase, and the R-Fe-B alloy powder containing the R2Fe17 phase, in which the amount of R is below 20 atomic %.
  • the magnet composition can be adjusted by blending the main phase R-Fe-B alloy powder, in which the amount of B is contained by 4 atomic % to 12 atomic % or more, and the adjusting R-Fe-B alloy powder containing the R2Fe17 phase, in which the amount of B is contained below 6 atomic %, or the adjusting R-Fe alloy powder containing the R2Fe17 phase, in which B is not contained.
  • the magnet composition can be adjusted by blending the adjusting R-Co (can be substituted by Fe) alloy powder containing the R-Co intermetallic compound (Nd3-Co, Nd-Co2 and the like).
  • Al of 9.5 atomic % or less Ti of 4.5 atomic % or less, V of 9.5 atomic % or less, Cr of 8.5 atomic % or less, Mn of 8.0 atomic % or less, Bi of 5 atomic % or less, Nb of 12.5 atomic % or less, Ta of 10.5 atomic % or less, Mo of 9.5 atomic % or less, W of 9.5 atomic % or less, Sb of 2.5 atomic % or less, Ge of 7 atomic % or less, Sn of 3.5 atomic % or less, Zr of 5.5 atomic % or less and Hf of 5.5 atomic % or less, to the alloy powder containing the R, B, Fe alloys or the R-Fe-B alloy containing Co or the blended R2Fe14B phase as the main phase, or to the adjusting alloy powder containing the R2Fe17 phase and the adjusting alloy powder containing the R-Co intermetallic compound phase, the alloy powder containing the R, B, Fe alloy
  • the R-B-Fe permanent magnet of the present invention it is indispensable that the R2Fe14B phase of the main phase of a crystal phase pregents above 90%, preferably, above 94%.
  • the R-Fe-B sintered magnet which is produced in a large lot at present, has the R2Fe14B phase of up to 90%, the high magnetic characteristics of the present invention, in which the value A + B is above 59, can not be obtained below 90%.
  • a degree of orientation of the magnet of the present invention is calculated from the aforementioned equation 1, it is indispensable that the degree of orientation of the magnet is above 85% to hold the value A + B above 59, and when the degree of orientation is below 85%, the squareness of demagnetization curve is deteriorated and the high residual magnetic flux density (Br) is lowered, results in a low (BH) max value.
  • the degree of orientation is preferably above 92%.
  • the squareness of demagnetization curve ⁇ (Br2/4)/(BH) max ⁇ theoretically shows a value of 1.00, since the above-mentioned degree of orientation is disturbed inevitably in the practical permanent magnet material, though it is limited to 1.05 even after many improvement in the past, in the permanent magnet materials of the present invention obtained by the aforementioned specific process, the value of the squareness of demagnetization curve is 1.01 to 1.045.
  • the main phase alloy powder containing the R2Fe14B phase as the main phase to which the adjusting alloy powder containing the R2Fe17 phase is added and blended, when R is below 11 atomic %, residual iron where R and B do not diffuse increases, and when exceeding 20 atomic %, the R-rich phase increases and the oxygen content increases at pulverization, so that R is preferably 11 atomic % to 20 atomic %, more preferably, 13 atomic % to 16 atomic %.
  • the high coercive force (iHc) can not be obtained when B is below 4 atomic %, and since the residual magnetic flux density (Br) is lowered when exceeding 12 atomic %, the good permanent magnet can not be obtained, so that B is preferably 4 atomic % to 12 atomic %, more preferably, 6 atomic % to 10 atomic %.
  • Fe is preferably within the range of 65 atomic % to 82 atomic %.
  • Fe is preferably 74 atomic % to 81 atomic %.
  • Co is preferably below 10 atomic % and Ni is preferably below 3 atomic %.
  • Fe is in the range of 55 atomic % to 72 atomic %.
  • the R-rich phase increases in production of the alloy powder and causes oxidation when the R exceeds 20 atomic %, thus R is preferably 5 to 15 atomic %.
  • B is below 6 atomic %, since only the R2Fe14B phase presents and the amount of B in the main phase alloy powder can be adjusted, B is preferably below 6 atomic %.
  • the rest is composed of Fe and unavoidable impurities, Fe is preferably 85 atomic % to 95 atomic %.
  • R is preferably 11 atomic % to 15 atomic %, more preferably, 12 atomic % to 14 atomic %.
  • B is preferably 4 atomic % to 12 atomic %, more preferably, 6 atomic % to 10 atomic %.
  • Fe is preferably 73 atomic % to 85 atomic %.
  • Fe is below 73 atomic %, the rare earth elements and B become abundant relatively and the R-rich phase and the B-rich phase increase, when exceeding 85 atomic %, the rare earth elements and B decrease relatively and the residual Fe increases, results in the non-uniform alloy powder, thus Fe is, more preferably, 76 atomic % to 82 atomic %.
  • Co is preferably below 10 atomic % and Ni below 3 atomic %.
  • Fe is preferably 63 atomic % to 82 atomic %.
  • the R-rich phase increases to cause oxidation in production of the alloy powder when R exceeds 45 atomic %, so that R is preferably 10 to 20 atomic %.
  • Co is preferably 55 atomic % to 95 atomic %.
  • One or two kinds of Fe and Ni substituted with Co in the adjusting alloy powder are that, since the oxidation resistance of the adjusting alloy powder is deteriorated when the amount of Fe is increased, and the coercive force of the magnet is lowered when the amount of Ni is increased, Fe is preferably below 50 atomic % and Ni below 10 atomic %. However, in the case of substituting a part of Co with Fe or Ni, Co is preferably 5 atomic % to 45 atomic %.
  • the magnet composition alloy powder, the main phase alloy powder containing the R2Fe14B phase as the main phase, and the adjusting alloy powder containing the R2Fe17 phase or the R-Co intermetallic compound phase are produced by, for example, a known strip casting process by a single roll process or a double roll process.
  • Hydrogenation processing is that, for example, a cast piece cut into a predetermined size and having the thickness of 0.03 mm to 10 mm is inserted into a material case, which is covered and charged into a container which can be closed tightly, after closing the container tightly, the container is vacuumed sufficiently, thereafter H2 gas of 200 Torr to 50 kg/cm2 pressure is introduced to occlude Hydrogenation by the cast piece.
  • the Hydrogenation reaction is an exothermic reaction
  • the H2 gas having a predetermined pressure for a fixed time
  • the H2 gas is absorbed and the cat piece is decayed spontaneously for pulverization.
  • the pulverized alloy is cooled and dehydrogenated in vacuum.
  • the processed alloy powder grains Since fine cracks are produced in the processed alloy powder grains, it can be pulverized by a ball mill, a jet mill and the like, and the alloy powder having the necessary grain size of 1 ⁇ m to 80 ⁇ m can be obtained.
  • air in the processing container may be substituted by inert gas beforehand, and then the inert gas is substituted by the H2 gas.
  • the H2 gas pressure is preferably 200 Torr to 50 kg/cm2. From a viewpoint of mass production, it is preferably 2 kg/cm2 to 10 kg/cm2.
  • the pulverization time by the Hydrogenation varies depending on the closed container size, the size of the cut piece and the H2 gas pressure, it takes more than 5 minutes.
  • the alloy powder pulverized by the Hydrogenation is subjected to a primary dehydrogenation in vacuum after cooling. Meanwhile, when the pulverized alloy is heated at 100°C to 750°C in vacuum or in argon gas, and subjected to a secondary dehydrogenation for 0.5 hours or longer, the H2 gas in the pulverized alloy can be completely removed, and oxidation of the powder or a molded body due to a prolonged preservation is prevented, thereby deterioration of the magnetic characteristics of the resulting permanent magnet can be prevented.
  • the dehydrogenation processing of the present invention heating up to 100°C or higher has a good dehydrogenating effect, the above-mentioned primary dehydrogenation in vacuum may be omitted, and the decayed powder may be directly dehydrogenated in vacuum or in an argon gas atmosphere at 100°C or higher.
  • the resulting decayed powder may be, subsequently, subjected to the dehydrogenation in the container atmosphere at 100°C or higher. Or after the dehydrogenation in vacuum, the decayed powder is taken out from the container for pulverization, thereafter, the dehydrogenation processing of the present invention heating up to 100°C or higher in the container may be effected again.
  • the preferable dehydrogenation temperature is 200°C to 600°C.
  • the processing time varies depending on the processing amount, it take 0.5 hours or longer.
  • Mean grain sizes of the powder at pulverization is preferably 1 ⁇ m to 10 ⁇ m. When below 1 ⁇ m, the pulverized powder becomes very active and susceptible to oxidation, thereby to trigger ignition. When exceeding 10 ⁇ m, un-pulverized coarse grain remains to cause deterioration of the coercive force and the slow sintering rate, results in a low density.
  • the mean grain size of the fine powder is, more preferably, 2 to 4 ⁇ m.
  • Pulverized powders are filled into a mold in an inert gas atmosphere.
  • the mold may be made of, besides non-magnetic metals and oxides, organic compounds such as plastics, rubber and the like.
  • a charging density of the powder is, from a bulk density (charging density 1.4 g.cm3) in a quiescent state of the powder, preferably within the range of the solidifying bulk density (charging density 3.0 g/cm3) after tapping.
  • the charging density is restricted to 1.4 to 3.0 g/cm3.
  • a pulse magnetic field by an air-core coil and a capacitor power source is applied for orientation of the powder.
  • the pulse magnetic field may be applied repeatedly, while compressing by upper and lower punches.
  • the pulse magnetic field intensity is larger the better, at least, more than 10 kOe is necessary, preferably, 30 kOe to 80 kOe.
  • the pulse magnetic field time is preferably 1 ⁇ sec to 10 sec, more preferably 5 ⁇ sec to 100 m sec, and an applying frequency of the magnetic field is preferably 1 to 10 times, more preferably, 1 to 5 times.
  • the oriented powder may be solidified by a hydrostatic press.
  • the hydrostatic pressing can be effected as it is.
  • Pressure by the hydrostatic pressing profess is preferably 0.5 ton/cm2 to 5 ton/cm2, more preferably, 1 ton/cm2 to 3 ton/cm2.
  • Pressure by the magnetic field pressing process is preferably 0.5 ton/cm2 to 5 ton/cm2, more preferably, 1 ton/cm2 to 3 ton/cm2.
  • a sheet cast piece having the thickness of about 1 mm is prepared from a molten alloy having compositions of Nd 13.0 - B 6.0 - Fe 81 obtained by melting in a high frequency melting furnace, by using a double-roll type strip caster including two copper rolls of 200 mm diameter. Crystal grain sizes of the cast piece are 0.5 ⁇ m to 15 ⁇ m in a short axial direction and 5 ⁇ m to 80 ⁇ m in a long axial direction, an R-rich phase which is finely separated into about 3 ⁇ m presenting as surrounding a main phase.
  • the oxygen content is 300 ppm.
  • the cast piece of 1000 g cut into a 50 mm square or smaller is contained in a closed container which can take in and discharge air, N2 gas is introduced into the container for 30 minutes and after substituting with air, H2 gas of 3 kg/cm2 pressure is fed into the container for 2 hours to decay the cast piece spontaneously by Hydrogenation, then retaining in vacuum at 500°C for 5 hours for dehydrogenation, thereafter cooling to room temperature and grinding into 100 mesh.
  • the 800 g of coarse grain in pulverized in a jet mill to obtain an alloy powder of 3.5 ⁇ m mean grain sizes.
  • the resulting alloy powder is filled into a rubber mold and a pulse magnetic field of 60 kOe is applied instantaneously for orientation, thereafter subjected to hydrostatic pressing at 2.5 T/cm2 by a hydrostatic press.
  • a molded body taken out from the mold is sintered at 1090°C for 3 hours to obtain a permanent magnet after the one hour annealing at 600°C.
  • Magnetic characteristics and density, crystal grain size, degree of orientation, the squareness of demagnetization curve main phase amount and oxygen content are shown in Table 1.
  • the molten alloy having the same composition as the Embodiment 1 is strip casted to obtain a sheet cast piece having the sheet thickness of about 0.5 ⁇ m.
  • Crystal grain sizes in the cast piece are 0.3 ⁇ m to 12 ⁇ m in a short axial direction and 5 ⁇ m to 70 ⁇ m in a long axial direction, an R-rich phase finely separated into about 3 ⁇ m presenting as surrounding a main phase.
  • the cast piece is pulverized by the jet mill at the same condition as the Embodiment 1 to obtain the alloy powder of about 3.4 ⁇ m mean grain size.
  • the powder is molded in the magnetic field of about 12 kOe, after, first, oriented in the pulse magnetic field of about 30 kOe, by a press machine, in which, as shown in Fig.
  • an alloy of Nd 13.5 - Dy 0.5 - B 6.5 - Co 1.0 - Fe 78.5 is strip casted to obtain a sheet cast piece.
  • the cast piece of 100 g cut into a 50 mm square or smaller is decayed spontaneously by the Hydrogenation as same as the Embodiment 1, and dehydrogenated in vacuum for 6 hours. Then, after coarse grinding, pulverized in a jet mill to obtain the powder of 3.5 ⁇ m mean grain size.
  • the resulting powder is oriented in the pulse magnetic field as same as the Embodiment 1, and a molded body obtained by the hydrostatic press is sintered similarly. Magnetic characteristics and density, crystal grain size, degree of orientation, the squareness of demagnetization curve, main phase amount and O2 content are shown in Table 1.
  • the powder obtained at the same condition as the Embodiment 1 is pressed and molded in the magnetic field of about 12 kOe by the usual magnetic field press machine in dried state, then sintered and annealed at the same condition as the Embodiment 1.
  • oxidation occurs during the pressing, thus densification to a sufficient sinter density is impossible, so that the magnetic characteristics can not be measured and only the density and O2 content are measured.
  • the coarse powder obtained at the same condition as the Embodiment 1 is pulverized by the ball mill, using toluene as a solvent, to obtain the fine powder of 3.5 ⁇ m mean grain size, which is pressed and molded in the magnetic field of about 12 kOe by the usual magnetic field press machine in a wet state, then sintered and annealed at the same condition as the Embodiment 1.
  • a molten alloy having the composition of Nd 14 - B 6.0 - Fe 80 obtained by melting in a high-frequency melting furnace is casted in an iron mold.
  • crystallization of a Fe primary crustal is seen, so that heated at 1050°C for 10 hours for homogeneous processing.
  • Crystal grain sizes of a resulting ingot are 30 to 150 ⁇ m in a short axial direction and 100 ⁇ m to several mm in a long axial direction, and an R-rich phase is segregated in the size of about 150 ⁇ m locally.
  • the coarse powder After coarsely grinding the alloy ingot, the coarse powder is obtained by the Hydrogenation and dehydrogenation by the same process as the Embodiment 1. Furthermore, the coarse powder is pulverised by the jet mill at the same condition as the Embodiment 1, and the resulting alloy powder of about 3.7 ⁇ m mean grain size is pressed and molded in the magnet field of about 12 kOe for sintering and heat treatment at the same conditions as the Embodiment 1. Magnetic characteristics and density, crystal grain size, degree orientation, the squareness of demagnetization curve, main phase amount and O2 content of the resulting permanent magnet are shown in Table 1.
  • the alloy powder is pressed in the magnetic field of about 12 kOe, sintered and annealed to obtain the permanent magnet. Magnetic characteristics and density, crystal grain size, degree of orientation, the squareness of demagnetisation curve, main phase amount and O2 content of the resulting permanent magnet are shown in Table 1.
  • An alloy having the composition of Nd 13.5 - Dy 0.5 - B 6.5 - Co 1.0 - Fe 78.5 is casted by the same method as the Comparative Example 3. Since a Fe primary crystal is crystallized in the resulting alloy ingot, which is subjected to the heat treatment at 1050°C for 6 hours. After coarsely grinding the alloy ingot, it is subjected to Hydrogenation as same as the Embodiment 1, and then dehydrogenated in vacuum. The coarse powder is ground coarsely and pulverized in the jet mill to obtain the powder of 3.7 ⁇ m mean grain size.
  • the powder is pressed in the magnetic field of about 12 kOe, then sintered and heated at the same condition as the Embodiment 1. Magnetic characteristics and density, crystal grain size, degree of orientation, the squareness of demagnetization curve, main phase amount and O2 content of the resulting permanent magnet are shown in Table 1.
  • the ingot After casting an alloy having the composition of Nd 16.5 - B 7 - Fe 76.5 into an ingot as same as the Comparative Example 3, without liquefaction, the ingot is ground coarsely, and as same as the Comparative Example 4, coarsely ground in the stamp mill, thereafter pulverized in the jet mill to obtain the fine powder of 3.7 ⁇ m mean grain size.
  • the fine powder is pressed in the magnetic field of about 12 kOe, then sintered and annealed at the same condition as the Embodiment 1. Magnetic characteristics and density, crystal grain size, degree of orientation, the squareness of demagnetization curve, main phase amount and O2 content of the resulting permanent magnet are shown in Table 1.
  • a main phase alloy powder by a strip casting process As materials for a main phase alloy powder by a strip casting process, 340 g a Nd metal of 99% purity, 8 g of a Dy metal of 99% purity, 65.5 g of a Fe-B alloy containing 20% B, and 600 g of an electrolytic iron of 99% purity are used, and melted in an Ar atmosphere so as to obtain an alloy having a predetermined composition, then casted by a strip casting process using copper rolls to obtain a cast piece having the plate thickness of about 2 mm. The cast piece is coarsely ground by a Hydrogenation processing, and pulverized by a jaw crusher, a disk mill and the like to obtain 800 g of powder of about 10 ⁇ m mean grain size.
  • the resulting powder consisting of 14.9 atomic % Nd, 0.1 atomic % Pr, 0.3 atomic % Dy, 8.0 atomic % B and Fe, is observed by an x-ray diffraction EPMA, as a result, it is confirmed that it is about 800 ppm.
  • the R2Fe14B main phase is about 5 ⁇ m in a short axial direction and 20 to 80 ⁇ m in a long axial direction, and the R-rich phase is finely dispersed as surrounding the main phase.
  • a Nd metal of 99% purity As materials of adjusting alloy powders containing an R2Fe17 phase by the strip casting process, 250 g of a Nd metal of 99% purity, 11 g of a Dy metal of 99% purity, 730 g of an electrolytic iron of 99% purity and 20 g of a Fe-B alloy containing 20.0% B are used, to obtain a cast piece having the plate thickness of about 2 mm as same as the main phase alloy. Furthermore, the powder is prepared by the same processing as the main phase alloy. A composition of the resulting powder is a 0.8 atomic % Nd, 0.1 atomic % Pr,0.4 atomic % dy, 2.4 atomic % B and Fe.
  • the 30% adjusting alloy powder is blended with the main phase alloy powder.
  • the material powders are fed into a grinder such as a jet mill and the like to pulverize into about 3 ⁇ m, the resulting fine Powder is filled into a rubber mold, and is subjected to hydrostatic pressing at 2.5 T/cm2 by a hydrostatic press machine, after applying a pulse magnetic field of 60 kOe instantaneously for orientation, thereby to obtain a molded body of 8 mm ⁇ 15 mm ⁇ 10 mm.
  • the molded body is sintered at 1100°C in the Ar atmosphere for 3 hours, and annealed at 550°C for one hour. Magnetic characteristics of the resulting magnet are shown in table 2.
  • the main phase alloy powder As materials for the main phase alloy powder, as same as the Embodiment 4, 340 g of a Nd metal of 99% purity, 8 g of a Dy metal of 99% purity, 600 g of an electrolytic iron of 99% purity and 65.5 g of a FE-B alloy containing 20% B are used, molten in the Ar atmosphere and casted in an iron mold. The resulting alloy ingot is pulverised into the powder of 10 ⁇ m mean grain size by the same method as the Embodiment 1. As the result of composition analysis, it is consisting of 14.9 atomic & Nd, 0.1 atomic % Pr, 0.3 atomic % Dy, 8.0 atomic % B and Fe. The oxygen content is about 900 ppm.
  • the R2Fe14B main phase is about 50 ⁇ m in a short axial direction and about 500 ⁇ m in a long axial direction, the R-rich phase omnipresents by 50 ⁇ m locally. Besides, ⁇ -Fe of 5 to 10 ⁇ m is seen in the main phase.
  • adjusting materials containing the R2Fe17 phase 200 g Md2O3 (98% purity), 12 g of Dy2O3 (99% purity), 65 g of a Fe-B alloy containing 20% B and 600 g of iron powders of 99% purity are used, to which 150 g of metal Ca of 99% purity and 25 g of CaCl2 anhydride are mixed, and charged into a stainless steel container to obtain the adjusting alloy powder by a direct reducing and diffusing process at 950°C for 8 hours in the Ar atmosphere.
  • the result of component analysis of the resulting alloy powder it is consisting of 10.8 atomic % Nd, 0.1 atomic % Pr, 0.4 atomic percent Dy, 2.4 atomic % B and Fe.
  • the oxygen content is 1500 ppm.
  • 30% adjusting alloy powder is blended with the main phase alloy powder and pulverized into about 3 ⁇ m in the grinder such as the jet mill and the like.
  • the resulting fine powder is oriented in the magnetic field of about 10 kOe, and molded at about 1.5 T/cm2 pressure at right angles to the magnetic field to obtain a molded body of 8 mm ⁇ 15 mm ⁇ 10 mm.
  • the molded body is sintered int he Ar atmosphere at 1100°C for 3 hours, and annealed at 550°C for one hour. Magnetic characteristic of the resulting magnet are also shown in Table 2.
  • the main phase alloy powder of the Comparative Example 1 is used, and as materials for the adjusting alloy powder, 250 g of a Nd metal of 99% purity, 11 g of Dy metal of 99% purity, 730 g of an electrolytic iron of 99% purity and 20 g of a Fe-B alloy containing 20.0 g B-are used, melted in the Ar atmosphere and casted in the iron mold. As the result of observation on the structure of the resulting alloy ingot, it is confirmed that a large amount of ⁇ -Fe is crystallized, so that the homogenizing processing is performed at 1000°C for 12 hours.
  • a Nd metal of 99% purity As materials, 315 g of a Nd metal of 99% purity, 8.5 g of a Dy metal of 99% purity, 52 g of a Fe-B alloy containing 20 % B and 636 g of an electrolytic iron of 99% purity are used, melted in the Ar atmosphere so as to obtain an alloy having a predetermined composition, then a cast piece having the plate thickness of about 2 mm is obtained by the strip casting process using copper rolls. Furthermore, the cast piece is coarsely ground by the Hydrogenation processing,then pulverized in the jaw crusher, disk mill and the like to obtain 800 g of powders of 10 ⁇ m mean grain size.
  • the resulting powder As the result of EPMA observation on the resulting powder, it is consisting of 13.8 atomic % Nd, 0.1 atomic % Pr, 0.3 atomic % Dy, 6.3 atomic % B and Fe.
  • the oxygen content is about 800 ppm.
  • the R2Fe14B main phase As the result EPMA observation also on the cast piece structure, the R2Fe14B main phase is about 6 ⁇ m in a short axial direction and 20 to 80 ⁇ m in a long axial direction, the R-rich phase presenting finely as surrounding the main phase.
  • a Nd metal of 99% purity As materials of he adjusting alloy powder containing the R2Fe17 phase, 125 g of a Nd metal of 99% purity, 5 g of a Dy metal of 99% purity and 275 g of an electrolytic iron of 99% purity are used, and a cast piece having the plate thickness of about 2 mm is obtained by the strip casting process as same as the main phase alloy. Furthermore, powder is prepared by the same processing as the main phase alloy. The composition of the resulting powder is 11.0 atomic % Nd, 0.05 atomic % Pr, 0.4 atomic % Dy and Fe.
  • 25 % adjusting alloy powder is blended with the main phase alloy powder.
  • the material powders are charged into a grinder such as a jet mill to pulverize into about 3 ⁇ m, then filled into a rubber mold, and the resulting fine powder is subjected to the hydrostatic pressing at 2.5 T/cm2 pressure by a Iso-static press machine to obtain a molded body of 8 mm ⁇ 15 mm ⁇ 10 mm, after applying the pulse magnet field of 60 kOe instantaneously for orientation.
  • the molded body is sintered in the Ar atmosphere at 1100°C for 3 hours, and annealed at 550°C for one hour. Magnetic characteristics of a resulting magnet are shown in Table 3.
  • the alloy having the same composition as the Embodiment 5 is casted in the iron mold to obtain the powder of about 10 ⁇ m mean grain size by the same method as the Embodiment 4.
  • Compositions are 14 atomic % Nd, 0.1 atomic % Pr, 0.5 atomic % Dy, 8 atomic % B and Fe, the oxygen content is about 900 ppm.
  • the result is about 50 ⁇ m in a short axial direction and about 500 ⁇ in a long axial direction
  • the R-rich phase omnipresents by 50 ⁇ m locally. Meanwhile, a part of 5 to 10 ⁇ m ⁇ -Fe presents in the main phase.
  • the adjusting alloy powder containing the R2Fe17 phase is produced by the same direct reducing and diffusing process as the Comparative Example 7, by using 280 g of Nd2O3 (purity 98%), 12 g of Dy2O3 (purity 99%) and 750 g of iron powder (purity 99%).
  • Components are 11.0 atomic % Nd, 0.05 atomic % Pr, 0.9 atomic % Dy and Fe.
  • the oxygen content is 1500 ppm.
  • 25% adjusting alloy powder is blended with the main phase alloy powder, and charged into the jet mill and the like to pulverize into about 3 ⁇ m.
  • the resulting fine powder is oriented in the magnet field of about 10 kOe, and molded at about 1.5 T/cm2 pressure at right angles to the magnetic field to obtain a molded body of 8 mm ⁇ 15 mm ⁇ 10 mm.
  • the molded body is sintered in the Ar atmosphere at 1100°C for 3 hours, and annealed at 550°C for one hour. Magnetic characteristics of the resulting magnet are also shown in Table 3.
  • the adjusting alloy powder is prepared, by melting 350 g of a Nd metal, 10 g of a Dy metal and 750 g of an electrolytic iron of 99% purity in the Ar atmosphere, and casted in the iron mold.
  • the homogenizing processing is effected at 1000°C for 12 hours.
  • it is consisting of 11.0 atomic % Nd, 0.05 atomic % Pr, 0.4 atomic % Dy and Fe.
  • the materials 300 g of a Nd metal, 13 g of a Dy metal, 50 g of a Fe-B alloy containing 20% B and 645 g of an electrolytic iron of 99% purity are used, and melted in the Ar atmosphere so as to obtain an alloy having a predetermined composition, then by the strip casting process using copper rolls, a cast piece having the plate thickness of about 2 mm is obtained. Furthermore, the cast piece is pulverised by the Hydrogenation, jaw crusher, disk mill and the like to obtain 800 g of powder of about 10 ⁇ m mean grain size.
  • the resulting powder is consisting of 13.3 atomic % Nd, 0.1 atomic % Pr, 0.5 atomic % Dy, 6 atomic % B and Fe.
  • the oxygen content is about 800 ppm.
  • the R2Fe14B main phase is about 0.3 to 15 ⁇ m in a short axial direction and about 5 to 90 ⁇ m in a long alloy direction, the R-rich phase presenting finely as surrounding the main phase.
  • a Nd metal of 99% purity As materials of the main phase alloy powder by the strip casting process, 260 g of a Nd metal of 99% purity, 23 g of a Dy metal of 99% purity, 68.5 g of a Fe-B alloy containing 20% B and 655 g of an electrolytic iron of 99% purity are used, and melted in the Ar atmosphere so as to obtain an alloy having predetermined composition, then casted by the strip casting process using copper rolls to obtain a cast piece having the plate thickness of about 2 mm.
  • the cast piece is coarsely ground by the Hydrogenation processing, and pulverised by a jaw crusher, a disk mill and the like to obtain 800 g of powder of about 10 ⁇ m mean grain size.
  • the resulting powder consisting of 11 atomic % Nd, 0.1 atomic % Pr, 1.0 atomic % Dy, 8 atomic % B and Fe is observed by an x-ray diffraction EPMA, as a result, it is confirmed that it is mostly consisting of a R2Fe14B phase.
  • the oxygen content is about 800 ppm.
  • the R2Fe14B main phase is about 0.5 to 1.5 ⁇ m in a short axial direction and 5 to 90 ⁇ m in a long axial direction, and the R-rich phase is finely dispersed as surrounding the main phase.
  • the adjusting alloy powder containing an R-Co intermetallic compound phase by the strip casting process As material of the adjusting alloy powder containing an R-Co intermetallic compound phase by the strip casting process, 490 g of a Nd metal, 2.6 g of a Dy metal and 500 g of Co of 99% purity are used, to obtain a cast piece having the plate thickness of about 2 mm as same as the main phase alloy. Meanwhile, by the same processing as the main phase alloy, powder is prepared. A composition of the resulting powder is 27.0 atomic % Nd, 0.5 atomic % Pr, 1.3 atomic % Dy and Co.
  • the cast piece structure is consisting of the R3Co phase and partly the R2Co17 phase, and the R3Co phase is dispersed finely.
  • the oxygen content in the powder of 10 ⁇ m mean grain size is 700 ppm.
  • 20% adjusting alloy powder is blended with the main phase alloy powder.
  • the material powders is charged into a grinder such as a jet mill and the like to pulverize into about 3 ⁇ m, which is filled into a rubber mold and is subjected to hydrostatic pressing at 2.5 T/cm2 by a hydrostatic press machine, after applying a pulse magnetic field of 60 kOe instantaneously for orientation, thereby to obtain a molded body of 8 mm ⁇ 15 mm ⁇ 10 mm.
  • the molded body is sintered at 1100°C in the Ar atmosphere for 3 hours, and annealed at 550°C for one hour. Magnetic characteristics of the resulting magnet are shown in Table 4.
  • Magnetic characteristics of the magnet obtained, by blending 10 % adjusting alloy powder with the main phase alloy powder prepared in the Embodiment 1, and magnetizing by the same process as the Embodiment 6 are shown in Table 4.
  • the main phase alloy powder As same as the Embodiment 6, 260 g of a Nd metal of 99% purity, 26 g of a Dy metal of 99% purity, 665 g of an electrolytic iron of 99% purity and 68.5 g of a Fe-B alloy containing 20.0% B are used, melted in the Ar atmosphere and casted in the iron mold.
  • the resulting alloy ingot is pulverized into powder of about 10 ⁇ m mean grain size by the same method as the Embodiment 1.
  • the powder is consisting of 11 atomic % Nd, 0.1 atomic % Pr, 1.0 atomic % Dy, 8 atomic % B and Fe, the oxygen content is about 900 ppm.
  • the R2Fe14B main phase is about 50 ⁇ m in a short axial direction and about 500 ⁇ m in a long axial direction, the R-rich phase omnipresents by 50 ⁇ m locally. A part of ⁇ -Fe of 5 to 10 ⁇ m present in the main phase.
  • the direct reducing and diffusing process As adjusting materials containing the R-Co intermetallic compound phase, by the direct reducing and diffusing process, 550 g of Nd2O3 (98% purity), 29 g of Dy2O3 (99% purity) and 500 g of Co powder of 99% purity are used, to which 350 g of metal Ca of 99% purity and 60 g of CaCl2 anhydride are mixed, and charged into a stainless steel container to obtain the alloy powder in the Ar atmosphere at 750°C for 8 hours. As the result of component analysis, the resulting alloy powder is consisting of 27.0 atomic % Nd, 0.6 atomic % Pr, 1.3 atomic % Dy and Co, the oxygen content is 1500 ppm.
  • 20 % adjusting alloy powder is blended with the main phase alloy powder, and charged into the grinder such as the jet mill and the like to pulverize into about 3 ⁇ m.
  • the resulting fine powder is oriented in the magnetic field of about 10 kOe, and molded at about 1.5 T/cm2 pressure at right of 8 mm x 15 mm x 10 mm.
  • the molded body is sintered in the Ar atmosphere at 1100°C for 3 hours, and annealed at 550°C for one hour. Magnetic characteristics of the resulting magnet are also shown in Table 4.
  • the adjusting alloy powder is prepared by melting. 490 g of a Nd metal, 26 g of Dy metal and 500 g of Co of 99% purity in the Ar atmosphere, and casted n the iron mold. As the result of observation on the resulting alloy ingot structure, a large amount of Co is crystallized, so that the homogenizing processing is effected at 800°C for 12 hours. As the result of component analysis, it is consisting of 11.0 atomic % Nd, 0.6 atomic % Pr, 1.3 atomic % Dy and Co.
  • a Nd metal As materials, 305 g of a Nd metal, 26 g of a Dy metal, 55 g of a Fe-B alloy containing 20% B, 100 g of Co of 99% purity, and 525 g of an electrolytic iron of 99% purity are used, melted in the Ar atmosphere so as to obtain an alloy having a predetermined composition, and by the strip casting process using copper rolls, a cast piece having the plate thickness of about 2 mm is obtained. The cast piece is coarsely ground by the Hydrogenation processing and pulverised by the jaw crusher, disk mill and the like to obtain 800 g of powder of about 10 ⁇ m grain size.
  • the resulting powder is consisting of 13.5 atomic % Nd, 0.1 atomic % Pr, 1.0 atomic % Dy, 6.7 atomic % B, 11.3 atomic % Co and Fe.
  • the oxygen content is about 800 ppm.
  • the R2(Fe, Co14)B phase is about 0.3 to 1.5 ⁇ m in a short axial direction and about 5 to 90 ⁇ m in a long axial direction, the R-rich phase and the R-Co phase presenting finely as surrounding the main phase.

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EP93308184A 1993-07-06 1993-10-14 Matériaux R-Fe-B pour aimants permanents et leurs procédé de fabrication Expired - Lifetime EP0633581B1 (fr)

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Cited By (22)

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Publication number Priority date Publication date Assignee Title
EP0706190A1 (fr) * 1994-10-07 1996-04-10 Sumitomo Special Metals Company Limited Méthodes de fabrication d'aimants permanents R-Fe-B
EP0753867A1 (fr) * 1995-07-12 1997-01-15 Hitachi Metals, Ltd. Aimant permanent à base de terre rare et sa méthode de production
EP1030317A3 (fr) * 1999-02-15 2001-01-03 Shin-Etsu Chemical Co., Ltd. Ruban rapidement trempé d' un alliage magnétique à base de terre rare/fer/ bore
EP1059645A3 (fr) * 1999-06-08 2001-01-03 Shin-Etsu Chemical Co., Ltd. Ruban mince d'un alliage de terre rare pour aimant permanent
US6527874B2 (en) 2000-07-10 2003-03-04 Sumitomo Special Metals Co., Ltd. Rare earth magnet and method for making same
EP1845536A3 (fr) * 2006-04-14 2008-06-25 Shin-Etsu Chemical Co., Ltd. Procédé de préparation d'un matériau pour aimant permanent aux terres rares
US7955442B2 (en) 2003-11-18 2011-06-07 Tdk Corporation Method for producing sintered magnet and alloy for sintered magnet
US8231740B2 (en) 2006-04-14 2012-07-31 Shin-Etsu Chemical Co., Ltd. Method for preparing rare earth permanent magnet material
EP2722856A1 (fr) * 2012-10-17 2014-04-23 Shin-Etsu Chemical Co., Ltd. Aimant fritté de terres rares et procédé de fabrication
US9715957B2 (en) 2013-02-07 2017-07-25 Regents Of The University Of Minnesota Iron nitride permanent magnet and technique for forming iron nitride permanent magnet
US9994949B2 (en) 2014-06-30 2018-06-12 Regents Of The University Of Minnesota Applied magnetic field synthesis and processing of iron nitride magnetic materials
US10002694B2 (en) 2014-08-08 2018-06-19 Regents Of The University Of Minnesota Inductor including alpha″-Fe16Z2 or alpha″-Fe16(NxZ1-x)2, where Z includes at least one of C, B, or O
US10068689B2 (en) 2011-08-17 2018-09-04 Regents Of The University Of Minnesota Iron nitride permanent magnet and technique for forming iron nitride permanent magnet
US10072356B2 (en) 2014-08-08 2018-09-11 Regents Of The University Of Minnesota Magnetic material including α″-Fe16(NxZ1-x)2 or a mixture of α″-Fe16Z2 and α″-Fe16N2, where Z includes at least one of C, B, or O
US10358716B2 (en) 2014-08-08 2019-07-23 Regents Of The University Of Minnesota Forming iron nitride hard magnetic materials using chemical vapor deposition or liquid phase epitaxy
US10504640B2 (en) 2013-06-27 2019-12-10 Regents Of The University Of Minnesota Iron nitride materials and magnets including iron nitride materials
US10573439B2 (en) 2014-08-08 2020-02-25 Regents Of The University Of Minnesota Multilayer iron nitride hard magnetic materials
US11195644B2 (en) 2014-03-28 2021-12-07 Regents Of The University Of Minnesota Iron nitride magnetic material including coated nanoparticles
US20220130580A1 (en) * 2020-10-22 2022-04-28 Toyota Jidosha Kabushiki Kaisha Rare earth magnet and method for producing thereof
US20240127993A1 (en) * 2022-10-13 2024-04-18 BAOTOU JINSHAN MAGNETIC MATERIAL Co.,Ltd. AUXILIARY ALLOY CASTING PIECE, HIGH-REMANENCE AND HIGH-COERCIVE FORCE NdFeB PERMANENT MAGNET, AND PREPARATION METHODS THEREOF
US12018386B2 (en) 2019-10-11 2024-06-25 Regents Of The University Of Minnesota Magnetic material including α″-Fe16(NxZ1-x)2 or a mixture of α″-Fe16Z2 and α″-Fe16N2, where Z includes at least one of C, B, or O
US12620511B2 (en) 2021-10-28 2026-05-05 Regents Of The University Of Minnesota Iron nitride magnetic material including coated nanoparticles

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KR100446193B1 (ko) * 2002-05-29 2004-08-30 주식회사 태평양금속 도전체 박막을 구비한 영구 자석 제조 방법 및 장치
US7618497B2 (en) * 2003-06-30 2009-11-17 Tdk Corporation R-T-B based rare earth permanent magnet and method for production thereof
CN100394518C (zh) * 2006-08-04 2008-06-11 北京工业大学 一种制备高矫顽力烧结稀土-铁-硼永磁材料的方法
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KR101375814B1 (ko) 2006-11-21 2014-03-20 가부시키가이샤 알박 배향체, 성형체 및 소결체의 제조 방법 및 영구자석의 제조 방법
CN101563739B (zh) * 2006-12-21 2013-03-06 株式会社爱发科 永磁铁及永磁铁的制造方法
WO2008075709A1 (fr) * 2006-12-21 2008-06-26 Ulvac, Inc. Aimant permanent et procédé de fabrication d'un aimant permanent
CN101393791B (zh) * 2007-09-21 2012-10-03 有研稀土新材料股份有限公司 一种各向异性粘结磁粉及其制备方法
KR101137395B1 (ko) * 2007-12-25 2012-04-20 가부시키가이샤 알박 영구자석의 제조 방법
CN101872668B (zh) * 2009-04-23 2014-06-25 北京中科三环高技术股份有限公司 具有优良磁化特性的烧结钕铁硼稀土永磁体及其制造方法
CN102087917B (zh) * 2009-12-02 2014-06-25 北京中科三环高技术股份有限公司 一种辐射取向磁环或多极磁环的制备方法及其压制设备
JP5572673B2 (ja) 2011-07-08 2014-08-13 昭和電工株式会社 Ｒ−ｔ−ｂ系希土類焼結磁石用合金、ｒ−ｔ−ｂ系希土類焼結磁石用合金の製造方法、ｒ−ｔ−ｂ系希土類焼結磁石用合金材料、ｒ−ｔ−ｂ系希土類焼結磁石、ｒ−ｔ−ｂ系希土類焼結磁石の製造方法およびモーター
JP5553461B2 (ja) 2011-12-27 2014-07-16 インターメタリックス株式会社 ＮｄＦｅＢ系焼結磁石
KR101485281B1 (ko) 2011-12-27 2015-01-21 인터메탈릭스 가부시키가이샤 NdFeB계 소결 자석
CN103887028B (zh) 2012-12-24 2017-07-28 北京中科三环高技术股份有限公司 一种烧结钕铁硼磁体及其制造方法
JP6238444B2 (ja) 2013-01-07 2017-11-29 昭和電工株式会社 Ｒ−ｔ−ｂ系希土類焼結磁石、ｒ−ｔ−ｂ系希土類焼結磁石用合金およびその製造方法
DE102016205243A1 (de) * 2016-03-30 2017-10-05 Thyssenkrupp Ag Vorrichtung und Verfahren zur Aufbereitung eines Probematerials
CN108481877B (zh) * 2018-03-10 2020-06-23 葛理想 电磁屏蔽用磁材的碎化处理工艺

Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS62291901A (ja) * 1986-06-12 1987-12-18 Toshiba Corp 永久磁石
EP0280372A1 (fr) * 1987-02-27 1988-08-31 Philips Electronics Uk Limited Procédé pour la fabrication d'aimants en alliage de métal de transition et/de terre rare
EP0304054A2 (fr) * 1987-08-19 1989-02-22 Mitsubishi Materials Corporation Poudre magnétique terre rare-fer-bore et son procédé de fabrication
JPH01119001A (ja) * 1987-10-30 1989-05-11 Kubota Ltd 希土類含有永久磁石粉末の製造方法
JPH0529117A (ja) * 1990-10-22 1993-02-05 Kawasaki Steel Corp 希土類−遷移金属系異方性磁粉の製造方法
EP0553527A1 (fr) * 1992-01-29 1993-08-04 Sumitomo Special Metals Co., Ltd. Matériau en poudre pour des aimants permanents à base de terre rare-fer-bore

Family Cites Families (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CA1316375C (fr) * 1982-08-21 1993-04-20 Masato Sagawa Materiaux magnetiques et aimants permanents
CN1051864C (zh) * 1986-08-04 2000-04-26 住友特殊金属株式会社 具有优异耐蚀性的稀土永磁体
SU1760563A1 (ru) * 1990-12-14 1992-09-07 Центральный научно-исследовательский институт черной металлургии им.И.П.Бардина Способ получени заготовки посто нного магнита
DE69202515T2 (de) * 1991-06-04 1995-09-21 Shinetsu Chemical Co Verfahren zur Herstellung von zweiphasigen Dauermagneten auf der Basis von Seltenen Erden.

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS62291901A (ja) * 1986-06-12 1987-12-18 Toshiba Corp 永久磁石
EP0280372A1 (fr) * 1987-02-27 1988-08-31 Philips Electronics Uk Limited Procédé pour la fabrication d'aimants en alliage de métal de transition et/de terre rare
EP0304054A2 (fr) * 1987-08-19 1989-02-22 Mitsubishi Materials Corporation Poudre magnétique terre rare-fer-bore et son procédé de fabrication
JPH01119001A (ja) * 1987-10-30 1989-05-11 Kubota Ltd 希土類含有永久磁石粉末の製造方法
JPH0529117A (ja) * 1990-10-22 1993-02-05 Kawasaki Steel Corp 希土類−遷移金属系異方性磁粉の製造方法
EP0553527A1 (fr) * 1992-01-29 1993-08-04 Sumitomo Special Metals Co., Ltd. Matériau en poudre pour des aimants permanents à base de terre rare-fer-bore

Non-Patent Citations (3)

* Cited by examiner, † Cited by third party
Title
DATABASE WPI Week 8805, Derwent World Patents Index; AN 88-032581 *
PATENT ABSTRACTS OF JAPAN vol. 13, no. 359 (E - 804) 10 August 1989 (1989-08-10) *
PATENT ABSTRACTS OF JAPAN vol. 17, no. 310 (E - 1380) 14 June 1993 (1993-06-14) *

Cited By (39)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0706190A1 (fr) * 1994-10-07 1996-04-10 Sumitomo Special Metals Company Limited Méthodes de fabrication d'aimants permanents R-Fe-B
EP0753867A1 (fr) * 1995-07-12 1997-01-15 Hitachi Metals, Ltd. Aimant permanent à base de terre rare et sa méthode de production
US5858123A (en) * 1995-07-12 1999-01-12 Hitachi Metals, Ltd. Rare earth permanent magnet and method for producing the same
US5997804A (en) * 1995-07-12 1999-12-07 Hitachi Metals Ltd. Rare earth permanent magnet and method for producing the same
US6080245A (en) * 1995-07-12 2000-06-27 Hitachi Metals, Ltd. Rare earth permanent magnet and method for producing the same
US6527822B2 (en) 1999-02-15 2003-03-04 Shin-Etsu Chemical Co., Ltd. Quenched thin ribbon of rare earth/iron/boron-based magnet alloy
EP1030317A3 (fr) * 1999-02-15 2001-01-03 Shin-Etsu Chemical Co., Ltd. Ruban rapidement trempé d' un alliage magnétique à base de terre rare/fer/ bore
US6319335B1 (en) 1999-02-15 2001-11-20 Shin-Etsu Chemical Co., Ltd. Quenched thin ribbon of rare earth/iron/boron-based magnet alloy
US6322637B1 (en) 1999-06-08 2001-11-27 Shin-Etsu Chemical Co., Ltd. Thin ribbon of rare earth-based permanent magnet alloy
US6419723B2 (en) 1999-06-08 2002-07-16 Shin-Etsu Chemical Co., Ltd. Thin ribbon of rare earth-based permanent magnet alloy
EP1059645A3 (fr) * 1999-06-08 2001-01-03 Shin-Etsu Chemical Co., Ltd. Ruban mince d'un alliage de terre rare pour aimant permanent
US6527874B2 (en) 2000-07-10 2003-03-04 Sumitomo Special Metals Co., Ltd. Rare earth magnet and method for making same
US7955442B2 (en) 2003-11-18 2011-06-07 Tdk Corporation Method for producing sintered magnet and alloy for sintered magnet
EP1845536A3 (fr) * 2006-04-14 2008-06-25 Shin-Etsu Chemical Co., Ltd. Procédé de préparation d'un matériau pour aimant permanent aux terres rares
US7955443B2 (en) 2006-04-14 2011-06-07 Shin-Etsu Chemical Co., Ltd. Method for preparing rare earth permanent magnet material
US8231740B2 (en) 2006-04-14 2012-07-31 Shin-Etsu Chemical Co., Ltd. Method for preparing rare earth permanent magnet material
US10068689B2 (en) 2011-08-17 2018-09-04 Regents Of The University Of Minnesota Iron nitride permanent magnet and technique for forming iron nitride permanent magnet
US12412686B2 (en) 2011-08-17 2025-09-09 Regents Of The University Of Minnesota Iron nitride permanent magnet and technique for forming iron nitride permanent magnet
US11742117B2 (en) 2011-08-17 2023-08-29 Regents Of The University Of Minnesota Iron nitride permanent magnet and technique for forming iron nitride permanent magnet
US9734947B2 (en) 2012-10-17 2017-08-15 Shin-Etsu Chemical Co., Ltd. Rare earth sintered magnet and making method
EP2722856A1 (fr) * 2012-10-17 2014-04-23 Shin-Etsu Chemical Co., Ltd. Aimant fritté de terres rares et procédé de fabrication
EP3410446A1 (fr) * 2012-10-17 2018-12-05 Shin-Etsu Chemical Co., Ltd. Aimant fritté anisotrope aux terres rares et procédé de fabrication
US11217371B2 (en) 2013-02-07 2022-01-04 Regents Of The University Of Minnesota Iron nitride permanent magnet and technique for forming iron nitride permanent magnet
US9715957B2 (en) 2013-02-07 2017-07-25 Regents Of The University Of Minnesota Iron nitride permanent magnet and technique for forming iron nitride permanent magnet
US10692635B2 (en) 2013-02-07 2020-06-23 Regents Of The University Of Minnesota Iron nitride permanent magnet and technique for forming iron nitride permanent magnet
US10504640B2 (en) 2013-06-27 2019-12-10 Regents Of The University Of Minnesota Iron nitride materials and magnets including iron nitride materials
US11195644B2 (en) 2014-03-28 2021-12-07 Regents Of The University Of Minnesota Iron nitride magnetic material including coated nanoparticles
US9994949B2 (en) 2014-06-30 2018-06-12 Regents Of The University Of Minnesota Applied magnetic field synthesis and processing of iron nitride magnetic materials
US12338536B2 (en) 2014-06-30 2025-06-24 Regents Of The University Of Minnesota Applied magnetic field synthesis and processing of iron nitride magnetic materials
US10961615B2 (en) 2014-06-30 2021-03-30 Regents Of The University Of Minnesota Applied magnetic field synthesis and processing of iron nitride magnetic materials
US10358716B2 (en) 2014-08-08 2019-07-23 Regents Of The University Of Minnesota Forming iron nitride hard magnetic materials using chemical vapor deposition or liquid phase epitaxy
US11214862B2 (en) 2014-08-08 2022-01-04 Regents Of The University Of Minnesota Forming iron nitride hard magnetic materials using chemical vapor deposition or liquid phase epitaxy
US10573439B2 (en) 2014-08-08 2020-02-25 Regents Of The University Of Minnesota Multilayer iron nitride hard magnetic materials
US10002694B2 (en) 2014-08-08 2018-06-19 Regents Of The University Of Minnesota Inductor including alpha″-Fe16Z2 or alpha″-Fe16(NxZ1-x)2, where Z includes at least one of C, B, or O
US10072356B2 (en) 2014-08-08 2018-09-11 Regents Of The University Of Minnesota Magnetic material including α″-Fe16(NxZ1-x)2 or a mixture of α″-Fe16Z2 and α″-Fe16N2, where Z includes at least one of C, B, or O
US12018386B2 (en) 2019-10-11 2024-06-25 Regents Of The University Of Minnesota Magnetic material including α″-Fe16(NxZ1-x)2 or a mixture of α″-Fe16Z2 and α″-Fe16N2, where Z includes at least one of C, B, or O
US20220130580A1 (en) * 2020-10-22 2022-04-28 Toyota Jidosha Kabushiki Kaisha Rare earth magnet and method for producing thereof
US12620511B2 (en) 2021-10-28 2026-05-05 Regents Of The University Of Minnesota Iron nitride magnetic material including coated nanoparticles
US20240127993A1 (en) * 2022-10-13 2024-04-18 BAOTOU JINSHAN MAGNETIC MATERIAL Co.,Ltd. AUXILIARY ALLOY CASTING PIECE, HIGH-REMANENCE AND HIGH-COERCIVE FORCE NdFeB PERMANENT MAGNET, AND PREPARATION METHODS THEREOF

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KR0131060B1 (en) 1998-04-24
DE69318147D1 (de) 1998-05-28
RU2113742C1 (ru) 1998-06-20
CN1076115C (zh) 2001-12-12
ATE165477T1 (de) 1998-05-15
TW272293B (fr) 1996-03-11
DE69318147T2 (de) 1998-11-12
CN1114779A (zh) 1996-01-10
KR950004295A (ko) 1995-02-17
EP0633581B1 (fr) 1998-04-22

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