WO2008075712A1 - 永久磁石及び永久磁石の製造方法 - Google Patents
永久磁石及び永久磁石の製造方法 Download PDFInfo
- Publication number
- WO2008075712A1 WO2008075712A1 PCT/JP2007/074407 JP2007074407W WO2008075712A1 WO 2008075712 A1 WO2008075712 A1 WO 2008075712A1 JP 2007074407 W JP2007074407 W JP 2007074407W WO 2008075712 A1 WO2008075712 A1 WO 2008075712A1
- Authority
- WO
- WIPO (PCT)
- Prior art keywords
- sintered magnet
- permanent magnet
- processing chamber
- magnet
- sintered
- Prior art date
Links
Classifications
-
- 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
- H01F1/06—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 in the form of particles, e.g. powder
- H01F1/08—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 in the form of particles, e.g. powder pressed, sintered, or bound together
-
- 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
- C22C38/06—Ferrous alloys, e.g. steel alloys containing aluminium
-
- 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
- C22C38/10—Ferrous alloys, e.g. steel alloys containing cobalt
-
- 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
- C22C38/12—Ferrous alloys, e.g. steel alloys containing tungsten, tantalum, molybdenum, vanadium, or niobium
-
- 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
- C22C38/16—Ferrous alloys, e.g. steel alloys containing copper
-
- 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
-
- 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
- H01F41/0293—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 diffusion of rare earth elements, e.g. Tb, Dy or Ho, into permanent magnets
-
- 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
Definitions
- the present invention relates to a permanent magnet and a method for producing the permanent magnet, and in particular, a permanent magnet having a high magnetic property obtained by diffusing Dy and Tb in a crystal grain boundary phase of an Nd—Fe—B sintered magnet.
- the present invention relates to a method for manufacturing the permanent magnet.
- Nd-Fe-B sintered magnets are inexpensive because they are made of a combination of iron and Nd and B elements that are inexpensive, abundant in resources, and can be stably supplied.
- the maximum energy product is about 10 times that of ferrite magnets
- it is used in various products such as electronic equipment.
- motors and generators for hybrid cars have been used. Adoption is also progressing.
- the Curie temperature of the sintered magnet is as low as about 300 ° C, the temperature may rise above a predetermined temperature depending on the usage condition of the product to be used. There is a problem of demagnetization.
- the sintered magnet when used in a desired product, the sintered magnet may be processed into a predetermined shape, and this processing may cause defects (cracks, etc.) or distortions in the crystal grains of the sintered magnet. This causes a problem that the magnetic properties are significantly deteriorated.
- a powder metallurgy method is known as an example of a method for producing an Nd-Fe-B-based sintered magnet.
- Nd, Fe, and B are blended at a predetermined composition ratio.
- An alloy raw material is prepared by melting and forging, and once coarsely pulverized by, for example, a hydrogen pulverization step, then finely pulverized by, for example, a jet mill pulverization step to obtain an alloy raw material powder.
- the obtained alloy raw material powder is oriented in a magnetic field (magnetic field orientation), and compression molded in a state where a magnetic field is applied to obtain a shaped body.
- the compact is then sintered under predetermined conditions to produce a sintered magnet.
- a uniaxial pressurization compression molding machine As a compression molding method in a magnetic field, a uniaxial pressurization compression molding machine is generally used. This compression molding machine fills a cavity formed in a through-hole of a die with alloy raw material powder, and forms a pair of upper and lower sides. The force that presses (presses) the alloy material powder from above and below with a punch to form the alloy material powder. During compression molding with a pair of punches, the friction between the alloy material powders filled in the cavity and the alloy material powder and the punch There is a problem that high orientation cannot be obtained due to friction with the set mold wall surface, and magnetic characteristics cannot be improved.
- a lubricant such as zinc stearate is added to the obtained alloy raw material powder to ensure the fluidity of the alloy raw material powder during compression molding in a magnetic field. It is known that the mold can be easily released from the mold (see Patent Document 2). (Improvement of magnetic force) / Park Ki, Tohoku University Doctoral thesis March 23, 2000)
- Patent Document 2 Japanese Patent Application Laid-Open No. 2004-6761 (see, for example, the description in the column of conventional technology) Disclosure of the Invention Problems to be solved by the invention
- the first object of the present invention is to efficiently diffuse Dy and Tb attached to the surface of a sintered magnet containing a lubricant into the grain boundary phase, and achieve high productivity and high productivity. It is an object of the present invention to provide a method for producing a permanent magnet capable of producing a permanent magnet having magnetic characteristics.
- a second object of the present invention is to provide a permanent magnet having high magnetic properties by efficiently diffusing Dy and Tb only in the grain boundary phase of an Nd Fe B-based sintered magnet containing a lubricant. It is in.
- the method of manufacturing a permanent magnet according to claim 1 includes at least a surface of a sintered magnet formed by sintering iron-boron rare-earth alloy raw material powder containing a lubricant.
- the first step of attaching at least one of Dy and Tb to a part, and at least one of Dy and Tb adhering to the surface of the sintered magnet after heat treatment at a predetermined temperature is applied to the grain boundaries of the sintered magnet.
- the sintered magnet is one having an average crystal grain size of 4 to 8 m. .
- the average crystal grain size of the sintered magnet in the range of 4111 to 8111, it is affected by carbon remaining in the sintered magnet (the lubricant ash).
- Dy and Tb adhering to the surface of the sintered magnet can be efficiently diffused into the grain boundary phase, and high productivity can be achieved.
- the average crystal grain size is less than 4 ⁇ , Dy and Tb diffuse into the grain boundary phase, and a permanent magnet with high coercive force can be obtained.
- the effect of adding a lubricant to the alloy raw material powder to improve the orientation by securing the alloy is diminished and the degree of orientation of the sintered magnet deteriorates.
- the residual magnetic flux density and the maximum energy product exhibiting magnetic properties are reduced.
- the coercive force is reduced because the crystal is large, and the surface area of the crystal grain boundary is reduced.
- the coercive force is further reduced by increasing the concentration ratio of the agent ash). Residual carbon reacts with Dy and Tb, which prevents Dy from diffusing into the grain boundary phase, and the diffusion time is long, resulting in poor productivity.
- the sintered magnet is arranged and heated in the processing chamber, and the evaporation material containing at least one of Dy and Tb arranged in the same or another processing chamber is heated and evaporated, and the evaporated evaporation material
- the adhering evaporation material Dy and Tb are attached to the sintered magnet surface before the thin film made of the evaporation material is formed on the sintered magnet surface. It is preferable to perform the first step and the second step by diffusing into the phase! /.
- the evaporated evaporation material is supplied to and adhered to the surface of the sintered magnet heated to a predetermined temperature.
- the sintered magnet was heated to a temperature at which an optimum diffusion rate was obtained, and the supply amount of the evaporation material on the surface of the sintered magnet was adjusted, so that the metal atoms of the evaporation material adhering to the surface were thin films.
- the metal atoms of the evaporation material adhering to the surface were thin films.
- are diffused sequentially into the grain boundary phase of the sintered magnet i.e., supply of metal atoms such as Dy and Tb to the surface of the sintered magnet and diffusion of the sintered magnet into the grain boundary phase). (Vacuum steam treatment)).
- the surface state of the permanent magnet is substantially the same as the state before the above treatment, and the manufactured permanent magnet surface is prevented from being deteriorated (surface roughness is deteriorated). Excessive diffusion of Dy and Tb in the grain boundary near the magnet surface is suppressed, eliminating the need for a separate post-process and achieving high V and productivity.
- Dy and Tb are diffused and uniformly distributed in the grain boundary phase of the sintered magnet, so that the Dy and Tb rich phase (Dy and Tb ranges from 5 to 80%) in the grain boundary phase.
- Dy and Tb diffuse only near the surface of the crystal grains.
- a permanent magnet with high coercive force and high magnetic properties can be obtained.
- defects occur in the crystal grains near the surface of the sintered magnet during processing of the sintered magnet, a Dy and Tb rich phase is formed inside the crack, resulting in magnetization and coercive force. Can be recovered.
- the specific surface area of the evaporating material arranged in the processing chamber is changed to increase or decrease the evaporation amount at a constant temperature, for example, a separate amount to increase or decrease the supply amount of the sintered magnet surface of Dy Tb.
- the amount of supply to the sintered magnet surface can be easily adjusted without changing the configuration of the equipment, such as by installing parts in the processing chamber.
- the inside of the processing chamber Prior to heating the processing chamber containing the sintered magnet in order to remove dirt, gas and water adsorbed on the surface of the sintered magnet before diffusing Dy and Tb into the grain boundary phase, It is preferable that the inside of the processing chamber is held at a predetermined pressure.
- the processing chamber is depressurized to a predetermined pressure and then heated and held at a predetermined temperature.
- the oxide film on the surface of the sintered magnet is removed before Dy and Tb are diffused into the grain boundary phase.
- the sintering by plasma is performed prior to heating the processing chamber containing the sintered magnet. It is preferable to clean the magnet surface.
- the permanent magnet according to claim 9 is obtained by sintering iron-boron rare earth alloy raw material powder containing a lubricant and having an average crystal grain size of 411 m 8 11 m.
- Dy Tb adhered to the surface of the sintered magnet by attaching at least one of Dy Tb to at least a part of the surface of the sintered magnet and applying heat treatment at a predetermined temperature. It is characterized in that at least one of these is diffused into the grain boundary phase of the sintered magnet.
- the method for producing a permanent magnet of the present invention can efficiently diffuse Dy Tb adhering to the surface of a sintered magnet containing a lubricant into the grain boundary phase, and can achieve high productivity and high magnetism.
- the effect is that a permanent magnet having the characteristics can be produced.
- the permanent magnet of the present invention has an effect that it has a particularly high coercive force and a high magnetic property.
- the permanent magnet M of the present invention evaporates the evaporation material V containing at least one of Dy and Tb, and converts the evaporated evaporation material V into a predetermined shape.
- the processed Nd-Fe-B sintered magnet S adheres to the surface of the S magnet, and the Dy and Tb metal atoms of the deposited evaporation material V are diffused into the grain boundary phase of the sintered magnet and spread uniformly. It is made by performing a series of treatments (vacuum steam treatment) at the same time.
- the Nd-Fe-B-based sintered magnet S which is a starting material, is produced by a known method as follows. That is, Fe, B, and Nd are blended at a predetermined composition ratio, and an alloy raw material of 0.05 mm to 0.5 mm is first manufactured by a known strip casting method. On the other hand, an alloy raw material having a thickness of about 5 mm may be produced by a known centrifugal forging method. In addition, a small amount of Cu, Zr, Dy, A1 or Ga may be added during blending. Next, the produced alloy raw material is once coarsely pulverized by a known hydrogen pulverization step, and then finely pulverized by a jet mill pulverization step to obtain an alloy raw material powder.
- the alloy raw material powder is improved in orientation by ensuring the fluidity of the alloy raw material powder and can be easily released from the mold. For this reason, a lubricant is added at a predetermined mixing ratio, and the surface of the alloy raw material powder is coated with this lubricant.
- a lubricant a fixed lubricant or a liquid lubricant having a low viscosity is used so as not to damage the mold.
- fixed lubricants layered compounds (MoS, WS, MoSe, graphite, BN, CFx, etc.), soft metals (Zn, Pb, etc.), hard substances (
- DIA powder, TiN powder, etc. organic polymers (PTEE, nylon aliphatic, higher aliphatic, fatty acid amide, fatty acid ester, metal stalagmite, etc.), especially zinc stearate It is preferable to use ethyleneamide or fluoroether grease.
- liquid lubricants include natural oils and fats (plant oils such as castor oil, coconut oil and palm oil, mineral oils, petroleum oils and the like), organic low molecular weight materials (lower aliphatic, lower Fatty acid amides and lower fatty acid esters). Liquid fatty acids, liquid fatty acid esters, and liquid fluorine-based lubricants are particularly preferred. Liquid lubricants can be used with surfactants or diluted with a solvent, and the residual carbon component of the lubricant remaining after sintering can be Since the coercive force is lowered, a low molecular weight material is desirable so that it can be easily removed in the sintering process.
- a solid lubricant When a solid lubricant is added to the alloy raw material powder P, it may be added at a mixing ratio of 0.02 to 0.1 wt%. If it is less than 0.02 wt%, the fluidity of the alloy raw material powder P will not be improved, and eventually the orientation will not be improved. On the other hand, if it exceeds 0.1 lwt%, when a sintered magnet is obtained, the coercive force decreases due to the influence of carbon remaining in the sintered magnet. Further, when a liquid lubricant is added to the alloy raw material powder P, it may be added at a rate in the range of 0.05 wt /% to 5 wt /%.
- the fluidity of the alloy raw material powder will not be improved, and eventually the orientation may not be improved.
- the sintered magnet is obtained when a sintered magnet is obtained.
- the coercive force decreases under the influence of carbon remaining in the magnet. If both a solid lubricant and a liquid lubricant are added to the lubricant, the lubricant spreads to every corner of the alloy raw material powder P, and higher orientation can be obtained due to a higher lubricating effect.
- an alloy raw material powder containing a lubricant is formed into a predetermined shape in a magnetic field using a uniaxial pressure-type compression molding machine (not shown) having a known structure, and then placed in a known sintering furnace.
- the sintered magnet is produced by storing and sintering under predetermined conditions.
- a vacuum vapor processing apparatus 1 for carrying out the process, a turbo molecular pump, cryopump, a predetermined pressure via the evacuating means 11 such as a diffusion pump (e.g. 1 X 10_ 5 Pa) It has a vacuum chamber 12 that can be kept under reduced pressure.
- a box 2 comprising a rectangular parallelepiped box 21 having an upper surface opened and a detachable lid 22 on the upper surface of the opened box 21 is installed.
- a flange 22a bent downward is formed on the outer peripheral edge of the lid 22 over the entire circumference.
- the flange 22a A processing chamber 20 is defined which is fitted to the outer wall (in this case, no vacuum seal such as a metal seal is provided) and is isolated from the vacuum chamber 11.
- a predetermined pressure of the vacuum chamber 12 through the vacuum exhaust means 11 e.g., 1 X 10- 5 Pa
- the processing chamber 20 is substantially half orders of magnitude higher pressure than the vacuum chamber 12 (e.g., 5 X 10- 4 The pressure is reduced to Pa).
- the volume of the processing chamber 20 is supplied to the sintered magnet S from a plurality of directions by direct or repeated collisions of Dy, Tb metal atoms, etc. in the vapor atmosphere in consideration of the mean free path of the evaporation material V.
- the wall thicknesses of the box portion 21 and the lid portion 22 are set so as not to be thermally deformed when heated by a heating means described later, and are made of a material that does not react with the evaporation material V.
- A1 atoms may enter the Dy and Tb vapor atmosphere. Therefore, whether the box 2 is made of, for example, Mo, W, V, Ta, or an alloy thereof (including rare earth-added Mo alloys, Ti-added Mo alloys), CaO, YO, or rare earth oxides. ,
- these materials are formed as a lining film on the surface of another heat insulating material.
- a plurality of Mo-made pieces are placed at a predetermined height position from the bottom in the processing chamber 20.
- a placement part 21a is formed by arranging wire rods (for example, ⁇ 0 ⁇ ;! to 10 mm) in a lattice shape, and a plurality of sintered magnets S can be placed side by side on the placement part 21a.
- the evaporation material V is appropriately disposed on the bottom surface, side surface, or top surface of the processing chamber 20.
- the evaporation material V As the evaporation material V, Dy or Tb which greatly improves the magnetocrystalline anisotropy of the main phase is used, and a fluoride containing at least one of Dy and Tb can be used. Further, Dy, Tb, or a fluoride thereof containing at least one of Nd and Pr may be used. In this case, the evaporation material V is blended at a predetermined mixing ratio, and for example, an arc melting alloy is obtained using an arc melting furnace, and is disposed in the processing chamber 20.
- the evaporation material V is Al, Ag, B, Ba, Be, C, Ca, Ce, Co, Cr, Cs, Cu, Er, Eu, Fe, Ga, Gd, Ge, Hf, and Ho.
- In, K, La, Li, Lu, Mg, Mn, Mo, Na, Nb, Ni, P, Pd, Ru, S, Sb, Si, Sm, Sn, Sr, Ta, Ti, Tm, V, W , Y, Yb, Zn, and Zr may further include at least one selected.
- the vacuum chamber 12 is also provided with heating means 3.
- the heating means 3 is made of a material that does not react with the evaporation material V such as Dy and Tb, like the box 2, and is provided so as to surround the box 2, for example, and has a reflective surface on the inside. It is composed of a heat insulating material made of Mo and an electric heater disposed inside thereof and having a filament made of Mo. Then, the inside of the processing chamber 20 can be heated substantially uniformly by heating the box 2 with the heating means 3 under reduced pressure and indirectly heating the inside of the processing chamber 20 via the box 2.
- the production of the permanent magnet M using the vacuum vapor processing apparatus 1 will be described.
- the sintered magnet S produced by the above method is placed on the placement portion 21a of the box portion 21 and Dy, which is the evaporation material V, is placed on the bottom surface of the box portion 21 (thereby, the inside of the processing chamber 20).
- the sintered magnet S and the evaporation material are spaced apart).
- the box body 2 is installed in a predetermined position surrounded by the heating means 3 in the vacuum chamber 12 (see FIG. 2).
- a predetermined pressure e.g., l X 10_ 4 Pa
- vacuum chamber 12 via the evacuation means 11 is evacuated to vacuum to reach, (the processing chamber 20 is evacuated to approximately half orders of magnitude higher pressure)
- the heating means 3 is activated to heat the processing chamber 20.
- the processing chamber 20 When the temperature in the processing chamber 20 reaches a predetermined temperature under reduced pressure, the processing chamber 20 is installed on the bottom surface of the processing chamber 20. Dy is heated to substantially the same temperature as the processing chamber 20 to start evaporation, and a Dy vapor atmosphere is formed in the processing chamber 20. When Dy starts to evaporate, the sintered magnets S and Dy are arranged apart from each other, so the melted Dy does not directly adhere to the sintered magnet S in which the surface Nd-rich phase is melted. Then, Dy atoms in the Dy vapor atmosphere are supplied to and adhered to the surface of the sintered magnet S heated to approximately the same temperature as Dy from a plurality of directions by direct or repeated collisions. Dy is diffused into the grain boundary phase of the sintered magnet S, and the permanent magnet M is obtained.
- the average composition of the sintered magnet surface S adjacent to the thin film becomes a Dy rich composition.
- the surface of the sintered magnet S melts (that is, the main phase melts and the amount of liquid phase increases).
- the vicinity of the surface of the sintered magnet S melts and collapses, and the unevenness increases.
- Dy penetrates excessively into the crystal grains with a large amount of liquid phase, and the maximum energy product and residual magnetic flux density, which show magnetic properties, are further reduced.
- the surface area (specific surface area) per unit volume is small at a ratio of !! to 10% by weight of the sintered magnet. It was placed on the bottom to reduce the amount of evaporation at a constant temperature.
- the heating means 3 is controlled so that the temperature in the processing chamber 20 is in the range of 800 ° C to 1050 ° C, preferably 900 ° C to 1000 ° C. (For example, when the temperature in the processing chamber is 900 ° C. to 100 ° C., the saturated vapor pressure of Dy is about 1 ⁇ 10 — 2 to 1 ⁇ 10 — &).
- the total surface area of the sintered magnet S installed on the mounting portion 21a of the processing chamber 20 is used to diffuse Dy into the grain boundary phase.
- the surface of the permanent magnet M is prevented from being deteriorated, and Dy is prevented from excessively diffusing into the grain boundary near the sintered magnet surface.
- the phase has a Dy-rich phase (a phase containing Dy in the range of 5 to 80%), and only near the surface of the grain The diffusion of Dy effectively improves the magnetization and coercivity, and in addition, yields a permanent magnet M with excellent productivity that does not require finishing.
- the operation of the heating means 3 is stopped, and 10 KPa is introduced into the processing chamber 20 via a gas introduction means (not shown).
- Ar gas is introduced, evaporation of the evaporation material V is stopped, and the temperature in the processing chamber 20 is temporarily lowered to 500 ° C., for example.
- the heating means 3 is operated again, the temperature in the processing chamber 20 is set in the range of 450 ° C. to 650 ° C., and heat treatment is performed to remove the distortion of the permanent magnet in order to further improve or recover the coercive force. Apply.
- the heating temperature range of the sintered magnet S that can increase the force diffusion rate described using Dy as the evaporation material as an example range from 900 ° C to 1000 ° C
- Tb having a low vapor pressure can be used, or an alloy of Dy and Tb may be used.
- the force of using the balta-like evaporation material V with a small specific surface area to reduce the evaporation amount at a constant temperature is not limited to this.
- a receiving tray having a concave section in the box portion 21 is used.
- an evaporation chamber (another processing chamber: not shown) is provided in the vacuum chamber 12 separately from the processing chamber 20, and other heating means for heating the evaporation chamber is provided, and the evaporation material is evaporated in the evaporation chamber. Then, the evaporating material V in the vapor atmosphere may be supplied to the sintered magnet in the processing chamber 20 via a communication path that connects the processing chamber 20 and the evaporation chamber.
- the evaporation material V is Tb
- the evaporation chamber may be heated in the range of 900 ° C to 1150 ° C.
- the force S described in the case of vacuum vapor treatment, Dy or Tb is applied to the surface of the sintered magnet using a known vapor deposition apparatus or sputtering apparatus. Adhering (first step), then, using a heat treatment furnace, Dy and Tb adhering to the surface are diffused into the grain boundary phase of the sintered magnet (second step) to obtain a permanent magnet
- the present invention can also be applied to a permanent magnet M having high magnetic properties.
- the vacuum chamber 12 is set in a predetermined manner via the vacuum exhaust means 11.
- pressure e.g., 1 X 10- 5 Pa
- the processing chamber 20 was reduced from the vacuum chamber 12 to approximately half orders of magnitude higher pressure (e.g., 5 X 10_ 4 Pa)
- the heating means 3 may be operated to heat the inside of the processing chamber 20 to, for example, 100 ° C. and hold it for a predetermined time.
- a plasma generator (not shown) having a known structure for generating Ar or He plasma is provided in the vacuum chamber 12, and the surface of the sintered magnet S by plasma prior to processing in the vacuum chamber 12 is provided. The cleaning pre-processing may be performed.
- a known transfer robot is installed in the vacuum chamber 12, and the lid 22 is installed in the vacuum chamber 12 after the tailing is completed. You just have to do it.
- the lid portion 22 is mounted on the upper surface of the box portion 21 to form the box body 2 !, but is isolated from the vacuum chamber 12 and is vacuum chamber.
- the processing chamber 20 can be decompressed as the pressure in the chamber 12 is reduced.
- the upper surface opening thereof is opened, for example, in Mo. It may be covered with a metal foil.
- the processing chamber 20 may be sealed in the vacuum chamber 12 and may be configured to be maintained at a predetermined pressure independently of the vacuum chamber 12.
- the sintered magnet S has a low oxygen content! /, And the extent to the grain boundary phase of Dy and Tb is increased. Since the diffusion rate is increased, the oxygen content of the sintered magnet S itself may be 3000 ppm or less, preferably 2000 ppm or less, more preferably lOOOppm or less.
- the well-known uniaxial pressurization type After filling the cavity of the compression molding machine and forming it into a predetermined shape in a magnetic field (molding process), the compact is placed in a known sintering furnace and sintered under a predetermined condition (firing). Tie process).
- the molding process and the sintering process were optimized, and a sintered magnet S was obtained so that the average crystal grain size was 2 ⁇ m-lO ⁇ m and the oxygen content was ⁇ OOppm.
- the average crystal grain size of the sintered magnet was determined by the line segment method after etching a surface perpendicular to the magnetic field orientation direction of the sintered magnet and drawing 10 random lines on the microscope composition photograph.
- the permanent magnet M was obtained by the vacuum vapor treatment using the vacuum vapor treatment apparatus 1.
- 100 sintered magnets S are arranged at equal intervals on the mounting portion 21a in the Mo box 2.
- Balta-like Dy having a purity of 99.9% was used as the evaporation material, and the total amount of 10 g was arranged on the bottom surface of the processing chamber 20.
- the vacuum evacuation means is activated and the vacuum chamber is once depressurized to 1 X 10_ 4 Pa (the pressure in the processing chamber is 5 X 10_ 3 Pa), and the heating temperature of the processing chamber 20 by the calo heat means 3 is 950 ° Set to C. Then, after reaching the temperature force S950 ° C.
- the above-described vacuum vapor treatment was performed in this state;! -72 hours, and then a heat treatment for removing the distortion of the permanent magnet was performed.
- the heat treatment temperature was set to 400 ° C and the treatment time was set to 90 minutes.
- the optimum vacuum steam treatment time (that is, the optimum diffusion time of Dy) for obtaining the highest magnetic properties was obtained.
- FIG. 5 is a table showing the magnetic characteristics as average values when permanent magnets are obtained under the above conditions. This According to the above, when the average crystal grain size is 3 m or less, or 9 m or more, the optimum vacuum steam processing time for obtaining the highest magnetic characteristics is 8 hours or more, and the productivity is poor. It can be seen that the coercive force cannot be effectively improved when the average crystal grain size is 9 m or more.
- the optimum vacuum steam treatment time is 4 to 6 hours
- the maximum energy product is 51MG0e or more
- the residual magnetic flux density is 14 It can be seen that a permanent magnet with a high magnetic property of 5 kG or more and a coercive force of about 30 k0e was obtained.
- FIG. 1 is a diagram schematically illustrating a cross section of a permanent magnet manufactured according to the present invention.
- FIG. 2 is a diagram schematically showing a vacuum processing apparatus for performing the processing of the present invention.
- FIG. 3 is a diagram schematically illustrating a cross section of a permanent magnet manufactured by a conventional technique.
- FIG. 4 (a) is a diagram for explaining processing deterioration of a sintered magnet surface. (B) is a figure explaining the surface state of the permanent magnet produced by implementation of this invention.
- FIG. 5 is a table showing the magnetic properties and optimum vacuum vapor treatment time of the permanent magnet produced in Example 1. Explanation of symbols
Landscapes
- Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- Materials Engineering (AREA)
- Mechanical Engineering (AREA)
- Metallurgy (AREA)
- Organic Chemistry (AREA)
- Power Engineering (AREA)
- Manufacturing & Machinery (AREA)
- Manufacturing Cores, Coils, And Magnets (AREA)
- Hard Magnetic Materials (AREA)
- Powder Metallurgy (AREA)
Abstract
Description
Claims
Priority Applications (5)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP2008550167A JP5328369B2 (ja) | 2006-12-21 | 2007-12-19 | 永久磁石及び永久磁石の製造方法 |
DE112007003091T DE112007003091T5 (de) | 2006-12-21 | 2007-12-19 | Permanetmagnet und Verfahren zu dessen Herstellung |
CN2007800473817A CN101563738B (zh) | 2006-12-21 | 2007-12-19 | 永磁铁及永磁铁的制造方法 |
KR1020097013015A KR101390443B1 (ko) | 2006-12-21 | 2007-12-19 | 영구자석 및 영구자석의 제조방법 |
US12/519,891 US8157926B2 (en) | 2006-12-21 | 2007-12-19 | Permanent magnet and method of manufacturing same |
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP2006344782 | 2006-12-21 | ||
JP2006-344782 | 2006-12-21 |
Publications (1)
Publication Number | Publication Date |
---|---|
WO2008075712A1 true WO2008075712A1 (ja) | 2008-06-26 |
Family
ID=39536339
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
PCT/JP2007/074407 WO2008075712A1 (ja) | 2006-12-21 | 2007-12-19 | 永久磁石及び永久磁石の製造方法 |
Country Status (9)
Country | Link |
---|---|
US (1) | US8157926B2 (ja) |
JP (1) | JP5328369B2 (ja) |
KR (1) | KR101390443B1 (ja) |
CN (1) | CN101563738B (ja) |
DE (1) | DE112007003091T5 (ja) |
RU (1) | RU2454298C2 (ja) |
SG (1) | SG177916A1 (ja) |
TW (1) | TWI431648B (ja) |
WO (1) | WO2008075712A1 (ja) |
Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP2022508370A (ja) * | 2018-12-29 | 2022-01-19 | 三環瓦克華(北京)磁性器件有限公司 | メッキ装置とメッキ方法 |
Families Citing this family (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US9082538B2 (en) * | 2008-12-01 | 2015-07-14 | Zhejiang University | Sintered Nd—Fe—B permanent magnet with high coercivity for high temperature applications |
WO2017077830A1 (ja) * | 2015-11-02 | 2017-05-11 | 日産自動車株式会社 | Nd-Fe-B系磁石の粒界改質方法、および当該方法により処理された粒界改質体 |
CN110444386B (zh) * | 2019-08-16 | 2021-09-03 | 包头天和磁材科技股份有限公司 | 烧结体、烧结永磁体及其制备方法 |
Citations (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP2005175138A (ja) * | 2003-12-10 | 2005-06-30 | Japan Science & Technology Agency | 耐熱性希土類磁石及びその製造方法 |
WO2006100968A1 (ja) * | 2005-03-18 | 2006-09-28 | Ulvac, Inc. | 成膜方法及び成膜装置並びに永久磁石及び永久磁石の製造方法 |
JP2006303433A (ja) * | 2005-03-23 | 2006-11-02 | Shin Etsu Chem Co Ltd | 希土類永久磁石 |
Family Cites Families (14)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPH08279406A (ja) * | 1995-04-06 | 1996-10-22 | Hitachi Metals Ltd | R−tm−b系永久磁石およびその製造方法 |
JP2001192705A (ja) * | 1999-10-25 | 2001-07-17 | Sumitomo Special Metals Co Ltd | 希土類合金粉末の成形体製造方法、成形装置および希土類磁石 |
RU2180142C2 (ru) * | 2000-01-12 | 2002-02-27 | ОАО Научно-производственное объединение "Магнетон" | Способ изготовления постоянных магнитов с высокой антикоррозионной стойкостью |
JP3422490B1 (ja) * | 2001-06-29 | 2003-06-30 | ティーディーケイ株式会社 | 希土類永久磁石 |
JP4353402B2 (ja) | 2002-03-27 | 2009-10-28 | Tdk株式会社 | 希土類永久磁石の製造方法 |
CN1217348C (zh) * | 2002-04-19 | 2005-08-31 | 昭和电工株式会社 | 在r-t-b系烧结磁铁的制造中使用的合金和r-t-b系烧结磁铁的制造方法 |
JP2005011973A (ja) * | 2003-06-18 | 2005-01-13 | Japan Science & Technology Agency | 希土類−鉄−ホウ素系磁石及びその製造方法 |
US7618497B2 (en) * | 2003-06-30 | 2009-11-17 | Tdk Corporation | R-T-B based rare earth permanent magnet and method for production thereof |
US8211327B2 (en) * | 2004-10-19 | 2012-07-03 | Shin-Etsu Chemical Co., Ltd. | Preparation of rare earth permanent magnet material |
MY142088A (en) | 2005-03-23 | 2010-09-15 | Shinetsu Chemical Co | Rare earth permanent magnet |
US20070089806A1 (en) * | 2005-10-21 | 2007-04-26 | Rolf Blank | Powders for rare earth magnets, rare earth magnets and methods for manufacturing the same |
JP4811143B2 (ja) * | 2006-06-08 | 2011-11-09 | 日立金属株式会社 | R−Fe−B系希土類焼結磁石およびその製造方法 |
WO2008023731A1 (en) * | 2006-08-23 | 2008-02-28 | Ulvac, Inc. | Permanent magnet and process for producing the same |
JP4840606B2 (ja) * | 2006-11-17 | 2011-12-21 | 信越化学工業株式会社 | 希土類永久磁石の製造方法 |
-
2007
- 2007-12-19 SG SG2011095502A patent/SG177916A1/en unknown
- 2007-12-19 US US12/519,891 patent/US8157926B2/en active Active
- 2007-12-19 WO PCT/JP2007/074407 patent/WO2008075712A1/ja active Application Filing
- 2007-12-19 JP JP2008550167A patent/JP5328369B2/ja not_active Expired - Fee Related
- 2007-12-19 CN CN2007800473817A patent/CN101563738B/zh active Active
- 2007-12-19 KR KR1020097013015A patent/KR101390443B1/ko active IP Right Grant
- 2007-12-19 DE DE112007003091T patent/DE112007003091T5/de not_active Ceased
- 2007-12-19 RU RU2009128022/02A patent/RU2454298C2/ru active
- 2007-12-20 TW TW096148991A patent/TWI431648B/zh not_active IP Right Cessation
Patent Citations (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP2005175138A (ja) * | 2003-12-10 | 2005-06-30 | Japan Science & Technology Agency | 耐熱性希土類磁石及びその製造方法 |
WO2006100968A1 (ja) * | 2005-03-18 | 2006-09-28 | Ulvac, Inc. | 成膜方法及び成膜装置並びに永久磁石及び永久磁石の製造方法 |
JP2006303433A (ja) * | 2005-03-23 | 2006-11-02 | Shin Etsu Chem Co Ltd | 希土類永久磁石 |
Cited By (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP2022508370A (ja) * | 2018-12-29 | 2022-01-19 | 三環瓦克華(北京)磁性器件有限公司 | メッキ装置とメッキ方法 |
JP7054761B2 (ja) | 2018-12-29 | 2022-04-14 | 三環瓦克華(北京)磁性器件有限公司 | メッキ装置とメッキ方法 |
US11920236B2 (en) | 2018-12-29 | 2024-03-05 | Sanvac (Beijing) Magnetics Co., Ltd. | Coating machine and coating method |
Also Published As
Publication number | Publication date |
---|---|
CN101563738B (zh) | 2012-05-09 |
RU2009128022A (ru) | 2011-01-27 |
JPWO2008075712A1 (ja) | 2010-04-15 |
JP5328369B2 (ja) | 2013-10-30 |
US20100051139A1 (en) | 2010-03-04 |
DE112007003091T5 (de) | 2009-11-05 |
US8157926B2 (en) | 2012-04-17 |
KR20090091310A (ko) | 2009-08-27 |
CN101563738A (zh) | 2009-10-21 |
RU2454298C2 (ru) | 2012-06-27 |
TW200849296A (en) | 2008-12-16 |
TWI431648B (zh) | 2014-03-21 |
SG177916A1 (en) | 2012-02-28 |
KR101390443B1 (ko) | 2014-04-30 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
JP5205277B2 (ja) | 永久磁石及び永久磁石の製造方法 | |
JP5247717B2 (ja) | 永久磁石の製造方法及び永久磁石 | |
TWI433172B (zh) | Method for manufacturing permanent magnets and permanent magnets | |
JP5277179B2 (ja) | 永久磁石の製造方法及び永久磁石 | |
WO2007102391A1 (ja) | R-Fe-B系希土類焼結磁石およびその製造方法 | |
JP5275043B2 (ja) | 永久磁石及び永久磁石の製造方法 | |
JPWO2009104632A1 (ja) | スクラップ磁石の再生方法 | |
JP2011035001A (ja) | 永久磁石の製造方法 | |
JP5205278B2 (ja) | 永久磁石及び永久磁石の製造方法 | |
JP5064930B2 (ja) | 永久磁石及び永久磁石の製造方法 | |
JP5328369B2 (ja) | 永久磁石及び永久磁石の製造方法 | |
JP4999661B2 (ja) | 永久磁石の製造方法 | |
JP4860491B2 (ja) | 永久磁石及び永久磁石の製造方法 | |
JP2010245392A (ja) | ネオジウム鉄ボロン系の焼結磁石 |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
WWE | Wipo information: entry into national phase |
Ref document number: 200780047381.7 Country of ref document: CN |
|
121 | Ep: the epo has been informed by wipo that ep was designated in this application |
Ref document number: 07850877 Country of ref document: EP Kind code of ref document: A1 |
|
WWE | Wipo information: entry into national phase |
Ref document number: 2008550167 Country of ref document: JP |
|
WWE | Wipo information: entry into national phase |
Ref document number: 12009501223 Country of ref document: PH |
|
WWE | Wipo information: entry into national phase |
Ref document number: 1020097013015 Country of ref document: KR |
|
WWE | Wipo information: entry into national phase |
Ref document number: 1120070030917 Country of ref document: DE |
|
WWE | Wipo information: entry into national phase |
Ref document number: 12519891 Country of ref document: US |
|
ENP | Entry into the national phase |
Ref document number: 2009128022 Country of ref document: RU Kind code of ref document: A |
|
RET | De translation (de og part 6b) |
Ref document number: 112007003091 Country of ref document: DE Date of ref document: 20091105 Kind code of ref document: P |
|
122 | Ep: pct application non-entry in european phase |
Ref document number: 07850877 Country of ref document: EP Kind code of ref document: A1 |