US3811962A - Large grain cobalt-samarium intermetallic permanent magnet material stabilized with zinc and process - Google Patents

Large grain cobalt-samarium intermetallic permanent magnet material stabilized with zinc and process Download PDF

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US3811962A
US3811962A US00244423A US24442372A US3811962A US 3811962 A US3811962 A US 3811962A US 00244423 A US00244423 A US 00244423A US 24442372 A US24442372 A US 24442372A US 3811962 A US3811962 A US 3811962A
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grains
zinc
microns
annealed
ranging
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M Benz
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General Electric Co
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General Electric Co
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Priority to US00244423A priority Critical patent/US3811962A/en
Priority to GB1399873A priority patent/GB1415918A/en
Priority to CA167,806A priority patent/CA985068A/en
Priority to NL7304872A priority patent/NL7304872A/xx
Priority to IT22651/73A priority patent/IT982726B/it
Priority to DE2319007A priority patent/DE2319007A1/de
Priority to ES413773A priority patent/ES413773A1/es
Priority to JP4229973A priority patent/JPS5722961B2/ja
Priority to BE130048A priority patent/BE798260A/xx
Priority to FR7313924A priority patent/FR2180897B1/fr
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    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01F—MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
    • H01F1/00—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties
    • H01F1/01—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties of inorganic materials
    • H01F1/03—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties of inorganic materials characterised by their coercivity
    • H01F1/032—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties of inorganic materials characterised by their coercivity of hard-magnetic materials
    • H01F1/04—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties of inorganic materials characterised by their coercivity of hard-magnetic materials metals or alloys
    • H01F1/06—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
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01F—MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
    • H01F1/00—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties
    • H01F1/01—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties of inorganic materials
    • H01F1/03—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties of inorganic materials characterised by their coercivity
    • H01F1/032—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties of inorganic materials characterised by their coercivity of hard-magnetic materials
    • H01F1/04—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties of inorganic materials characterised by their coercivity of hard-magnetic materials metals or alloys
    • H01F1/047—Alloys characterised by their composition
    • H01F1/053—Alloys characterised by their composition containing rare earth metals
    • H01F1/055—Alloys characterised by their composition containing rare earth metals and magnetic transition metals, e.g. SmCo5
    • H01F1/0551—Alloys characterised by their composition containing rare earth metals and magnetic transition metals, e.g. SmCo5 in the form of particles, e.g. rapid quenched powders or ribbon flakes
    • H01F1/0552—Alloys characterised by their composition containing rare earth metals and magnetic transition metals, e.g. SmCo5 in the form of particles, e.g. rapid quenched powders or ribbon flakes with a protective layer
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01F—MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
    • H01F13/00—Apparatus or processes for magnetising or demagnetising
    • H01F13/003—Methods and devices for magnetising permanent magnets

Definitions

  • the annealed body is then comminuted to a grain size corresponding to or smaller than the grain size of the cast body and ranging from about 50 microns to 200 microns.
  • the free annealed grains are admixed with 1-15% by weight zinc powder and the resulting mixture is heated to melt the zinc powder to form a continuous coating of zinc on the individual grains.
  • the present invention relates generally to the art of permanent magnets.
  • it is concerned with making large grain cobalt-samarium intermetallic permanent magnet material having unique permanent magnet properties which are stabilized with zinc.
  • permanent magnets comprised of the novel zinc-coated grains bonded to a non-magnetic making permanent magnets has been developed based on cobalt and rare-earth elements, particularly cobalt and samarium.
  • the improvement over prior art materials is so great that the cobalt-rare earth magnets stand in a class by themselves.
  • the new materials are superior to convenvtional magnets of the Alnico and ferrite type, and their magnetic energy is significantly greater. Since more powerful the magnet for a given size is the smaller it can be for a given job, the cobalt-rare earth intermetallic magnets have applications for which prior art materials not even be considered.
  • Permanent magnet properties of bulk cobalt-rare earth intermetallic bodies are enhanced by reducing them to a powder.
  • the as-ground powder can be incorporated in canbonding media to produce a composite finished permaproperties of the material fall significantly.
  • direct reduction of a cobalt-samarium intermetallic bulk body to grains having a size as low as 50 microns results in a material having such poor properties as to b useless for permanent magnet applications.
  • the permanent magnet properties of the disclosed grains of the aforementioned copending patent application tend to deteriorate in air at high temperatures, i.e. temperatures of about 150 C.
  • the present application provides a method for stabilizing the permanent magnet properties of these grains in air at temperatures ofabout 150 C.
  • the cast body is annealed in an atmosphere in which it is substantially inert at a temperature ranging from about 900 C. up to a temperature below its melting point for a period of time ranging from about 5 minutes to 24 hours.
  • the annealing temperature ranges from about 900 C. to 1200 C. since no significant improvement in magnetic properties is produced at temperatures significantly higher than 1200 C.
  • Annealing time for a particular annealing temperature depends on the particular permanent magnet properties desired.
  • the annealed body is then comminuted to a grain size corresponding to or smaller than the grain size of the cast body and ranging from about 50 to 200 microns.
  • the cast body prior to annealing, can be comminuted to a'grain size corresponding to its grain size or smaller than its grain size and the resulting free grains, ranging in size from about 50 to 200 microns, are annealed at a temperature ranging from about 900 C. to 1200 C. for a period of time ranging from about 5- minutes to 24 hours.
  • annealing time for a particular annealing temperature depends on the particular permanent magnet properties desired, and for significantly useful permanent magnet properties, the free grains should -be annealed for a period of time sufiicient for the annealed free grains to show at room temperature, after being magnetized to at least approach saturation magnetization, i.e.
  • the free annealed grains are admixed with zinc powder in an amount of about 1% to 15% by weight of said grains and the resulting mixture is heated to melt the zinc powder to form a continuous coating of zinc on the individual grains.
  • the cobalt-samarium alloy of the present invention contains samarium in an amount of about 34 to 38 percent by weight of the alloy, and generally, to attain the best magnetic properties, it contains samarium in an amount of about 35 percent by weight of the alloy. Grains produced in accordance with the present process but having a cobaltsamarium composition outside this range do not produce satisfactory permanent magnets.
  • the alloy is prepared in an atmosphere in which cobalt and samarium are substantially inert such as a noble gas or under a vacuum by a number of methods such as, for example, by induction or arc melting the cobalt and samarium.
  • the molten alloy should, preferably, also be cooled in an atmosphere in which it is substantially inert such as a noble gas or under a vacuum.
  • the cobalt-Samarium alloy is cooled at a rate sufiiciently slow to produce a solid cast body wherein the grains range -in size from 100 to 1000 microns.
  • This can be determined empirically using standard metallurgical techniques such as, for example, casting a liquid melt in a heated mold or simply allowing the molten alloy to cool in a crucible at room temperature.
  • cooling should be carried out in an atmosphere in which the alloy is substantially inert such as a noble gas or a vacuum.
  • the solid cast body should have grains with a minimum size of about 100 microns since it would be difiicult and not practical to 'try to obtain the required amount of the present single are smaller than 100 microns.
  • the large grain solid cobalt-Samarium intermetallic cast body can then be annealed or, alternatively, the cast body can be comminuted and the resulting free grains annealed.
  • Annealing is carried out in an atmosphere in which the cobalt-samarium intermetallic material is substantially inert such as argon or in a vacuum. If the body is comminuted to free grains prior to annealing, the free grains also should be annealed in a container made of a material to which it is substantially inert such 'as molybdenum, tantalum or niobium to prevent contamination. Annealing can be carried out at a temperature ranging from about 900 C. up to a temperature below the melting point 1200 C.
  • the particular annealing time period for a particular annealing temperature depends largely on the specific permanent magnet properties desired. To produce significantly useful permanent magnet properties, it should be sufficiently long to produce an annealed material having the inherent property of showing at room temperature, after being magnetized to at least approach saturation magnetization, a relative magnetization value 41rl/B, of at least 50 percent at a demagnetizing field of--4 kilooersteds. Generally, the longer the material is annealed, the higher its relative magnetization value becomes at higher demagnetizing fields, i.e. demagnetizing fields of --4 kilooersteds and higher.
  • annealing the cobalt-samarium alloy at a temperature ranging from about 1100 C. to 1200 C. for a period of 10 hours should produce free grains having a relative magnetization value of at least 50 percent or 0.5 at a demagnetizing field of 10 kilooersteds. Generally, after an annealing period of 24 hours. no significant improvement in permanent magnet properties occurs.
  • the term relative magnetization as used herein is the ratio of magnetization 41rJ to remanent induction B,.. Specifically, when a magnetic field is applied to a permanent magnet material, a magnetization value of 41r] gauss is established therein. When the magnetic field is removed, the material has a remanent induction 8,.
  • the intrinsic coercive force H is the field strength at which the mag netization 41rJ is zero and is a measure of a permanent magnets resistance to demagnetization.
  • An additional measure of a permanent magnets resistance to demagnetization is the shape of the hysteresis loop in the second quadrant wherein magnetization 41] or relative magnetization 41rJ/B verses a negative field H which shows what positive values of magnetization can be maintained in the presence of the demagnetizing field H.
  • the present cobalt-samarium alloy in solid bulk form has a saturation magnetization 41rJ value of about 9000 to 11,000 gauss. This is the maxiumum magnetization value achievable for this cobalt-samarium composition in solid bulk form.
  • free grains of this cobaltsamarium alloy when incorporated in a non-magnetic matrix to a volume fraction of about one-half, having an alignment factor of 1.00 and magnetized to saturation, should have a saturation magnetization 41rJ of about 4500 gauss to 5500 gaus, a remanent induction B of about 4500 gauss to 5500 gauss and maintain a magnetization value of about 4500 gauss to 5500 gauss at a demagnetizing field of about 4 kilooersteds.
  • the free grains when the free grains are incorporated in the non-magnetic matrix to a volume fraction of about one-half and magnetically aligned therein along their easy axis of magnetization so as to have an alignment factor of about 0.95 and magnetized to saturation or approaching saturation magnetization, i.e. within about ten percent of full saturation magnetization the resulting permanent magnet has typically, a magnetization value 41rJ of about 4000 gauss at a demagnetizing field of -4 kilooersteds.
  • the present free grains incorporated in a non-magnetic matrix to a volume fraction of one-half i.e.
  • the annealed material is cooled in an atmosphere in which itis substantially inert such as, for example, argon or nitrogen, or it may be cooled in a vacuum, and generally, it is cooled to room temperature.
  • substantially inert such as, for example, argon or nitrogen
  • the cast body can be comminuted to free grains by a number of conventional methods, such as, for example, by crushing by mortar and pestle, double disc pulverizer, or jaw crushers. Comminution is preferably carried out in an atmosphere in which the material is substantially inert such as argon'or under a vacuum.
  • the grains of the cast cobaltsamarium body are single crystals and the cast body is comminuted to free grains having a size corresponding to the grain size of the cast body, or it is comminuted to free grains having a size smaller than the grain size of the cast body.
  • the free grains have a size ranging from about 50 microns to 200 microns. Free grains having a size significantly larger than 200 microns do not have useful permanent magnet properties.
  • comminution should be carried out so that a major portion, i.e. at
  • the free grains are single crystal free grains.
  • the single crystal structure of the free grains is determinable by standard metallographic tech niques such as, for example, X-ray diffraction techniques.
  • at least 95 percent by weight or substantially all of the resulting free grains are single crystal grains. Since the Weakest bonds in the cast body exist at the grain boundaries, it is at these boundaries that breakage of the cast body usually preferentially occurs during comminution. In practice, due to breakage, the cast body should preferably have a grain size larger than that desired for the free grains to produce the highest amount of free grains of a single crystal.
  • the free annealed grains are admixed with zinc pow der, preferably at room temperature, in an amount of about 1% to 15% by weight of said free annealed grains which range in size from about 50 microns to 200 microns.
  • the zinc is used in an amount of about 1-5% by weight of said grains. Since the smaller sized free grains have a larger total surface area, they generally require the larger amounts of zinc powder.
  • the zinc powder should not be larger than about 150 microns, and generally, ranges in size from about 40 to 100 microns.
  • the annealed free grains and the zinc powder can be mixed in 'air'by a number of conventional techniques such as simply stirring together or tumbling. Occasion-.
  • a liquid in which the mixture is substantially inert such as isopropyl alcohol can be included in the mixture to promote the production of a thorough mixture.
  • the resulting mixture is heated in an atmosphere in which it is substantially inert at a temperature which fuses or melts the zinc powder which, in the present invention, generally ranges from about 400 C. to about 475 C., and preferably, it is about 450 C. Temperatures higher than 500 C. should not be used since they would tend to diffuse the zinc into the grains too rapidly.
  • the mixture is heated for a period of time sufiicient to form a continuous coating of zinc on the individual grains but insufficient to diffuse the zinc into the grains to deterio rate their permanent magnet properties to any significant extent. This time period can be determined empirically, and generally, at temperatures ranging from about 425 C. to about 450 C., the time period may range from about 15 to about 60 minutes.
  • the zinc coating formed on the grains should be sufliciently thick to maintain the magnetic stability of the grains in air at elevated temperatures of about 150 C.
  • the thickness of the zinc coating should be suflicient to prevent air from penetrating to the cobalt-samarium grain surface.
  • the outer portion of the zinc coating should be available to be oxidized by the air leaving an inner continuous zinc coating to maintain the stability of the permanent magnet properties of the grains in air at elevated temperatures.
  • grains having a size of microns coated with zinc in an amount of 5% by weight of the grains have a zinc coating 2.5 microns in thickness.
  • the use of the zinc in an amount of 1% to 15% by weight of the free grains has substantially no deteriorating effect on the permanent magnet properties of the grains and in some instances improves these properties. Amounts of zinc significantly in excess of 15 by weight of the free grains does not improve magnetic stability and would prevent a close packing of the grains in the non-magnetic matrix thereby diluting the permanent magnet properties somewhat.
  • the zinc-coated free grains of the present invention are incorporated in a non-magnetic matrix to form permanent magnets.
  • the zinc-coated grains are incorporated into the non-magnetic matrix and, while the matrix is kept in a condition sufficiently liquid to maintain the grains in a substantially unlocked position, an aligning magnetizing field is applied to the incorporated grains to align them substantially along their preferred axis of magnetization which is the C or easy axis of magnetization, and, if desired, also to magnetize them as required.
  • the incorporated single crystal grains subjected to the magnetizing field will be able to turn in a direction most favorable from a magnetic point of view, i.e.
  • an additional magnetizing field may be applied to the locked aligned grains to magnetize them to full saturation or to approach saturation magnetization and the specific strength of this magnetizing field depends largely on the degree of alignment of the grains.
  • a magnetizing field ranges from about 10 kilooersteds to 100 kilooersteds.
  • the zinc-coated free grains of the present invention can be magnetized to approach saturation, then incorporated in the liquid nonmagnetic matrix,,and an aligning magnetic field applied to the incorporated magnetized grains to align them along their easy axis of magnetization before the matrix is solidi fraction of about 50 percent by volume.
  • Permanent magnets having useful permanent magnet properties for a wide range of applications are produced when the zinc-coated grains of the present invention are incorporated in a non-magnetic matrix and magnetized. Specifically, the resulting permanent magnets have a useful substantially stable magnetization 411-1 in air at temperatures as high as about C.
  • the permanent magnets of the present invention 'areuseful in telephones, electric clocks, radios, television, and phonographs. They are also useful in portable appliances, such as electric toothbrushes and electric knives, and to operate automobile ac- .cessories. In industrial equipment, the present permanent magnets can be used in such diverse applications as meters 1 Relative magnetization 471' J/B,:
  • the grain structure of the solid cast cobalt-samarlum Specifically, the zinc powder used for all, these samples body was dete mined by slic ng oil a portlon of the caSthad a size of about 50 microns. The indicated amount of 11g, pol shing 1t and examining it under a microscopezinc powder was stirred with the annealed grains in air The size of the free grams 'was determined by standard 15 at room temperature and occasionally with the inclusion technlqlles 1 8 Us Standard Screen Y of a small amount of isopropyl alcohol to improve wetting All magnetic measurements were carried out at room of h in powder onto the grains to produce a' thorough temperature. 1 mixture.
  • each resulting sample mixture was heated in an Under the condit ons set forth 1n the following examatmosphere of ur argon at the temperature and for the p the resultmg ahgnmentifactor was at least about 0.85 time eriod indicated in the following table.
  • the grams were a h g to at least pp h satw pletion of the heating, each sample was transferred to a I'alZlOIl magnetlzat on ne. Wlthlll about 10 percent of full chamber having an atmosphere of argon at room tem- Salllfatlon magnetllatlonperature Where it cooled to room temperature.
  • Samples EXAMPLE 1 4-12 and 15-18 appeared to have a continuous coating of Zinc thereon.
  • the crucible was broken with a hammer.
  • the grains kilooersteds was then applied to the incorporated sample in the cast alloy ranged in size from about 100 microns to align the grains along their easy axis of magnetization to 1000 microns. and the wax was cooled in the aligning magnetic field
  • the solid cast alloy was comminuted in a nitrogen atuntil it solidified to lock the magnetically aligned grains mosphere by means of a double disc pulverizer and a in position.
  • Samples 13-18 there was applied to the batch of free grains having a size ranging from about 104 magnetically aligned locked grains, 9.
  • magnetizing field microns to 147 microns was recovered therefrom with of 60 kilooersteds. about 95% of these recovered grains being single crystal Relative magnetization 41rJ/B, was measured at demagfree grains. A portion of this batch was used to form netizing fields starting from zero demagnetizing field. At Sample 13, the as-ground sample in the following table. zero demagnetizing field, relative magnetization. 41rJ/B The remaining portion of this batch of free grains was has, by definition, avalue of 1.00.
  • Sample 3 After 18 hours in air at 150 C., Sample 3, which was not treated with zinc, shows that its resistance to demagnetization fell significantly at a demagnetizing field of 3 kilooersteds, whereas Sample 6, which was zinc-coated in accordance with the present "invention, exhibited good resistance to demagnetization at a demagnetizing'field of -4 kilooersteds. Also, Sample 12, which was zinc-coated in accordance with the present invention, after 16 hours at 150 C. in air, showed good resistance to demagnetization at demagnetizing fields as high as 9 kilooersteds.
  • EXAMPLE 2 A magnetized sample of zinc-coated annealed free grains was prepared as set forth for Sample of Example 1 except that the zinc-coated annealed grains were packed to a volume fraction of .39 or 39 percent. v
  • This sample had an alignment factor A of 0.94, a remanent induction B, of 0.03 kG., a coercive force H, of 2.9 kOe., a maximum energy product (BH) of 2.3 MGOe., and an intrinsic coercive force H of 18 kOe.
  • the resistance to demagnetization of this sample is shown in the accompanying figure and shows what high magnetization values can be maintained at room temperature at relatively high demagnetizing fields.
  • said annealing being carried out so that said resulting recovered free grains have the property of showing at room temperature after being magnetized to at least within about 10 percent of full saturation magnetization a relative magnetization value 4 1rJ/B, of at least 50 percent at a demagnetizing field of 4 kilooersteds, admixing said recovered free grains with zinc powders in an amount ranging from about 1 to 15 percent by weight of said grains, and heating the resulting mixture at a temperature ranging from 400 C. to 500 C. in an atmosphere in which said mixture is substantially inert to form a continuous zinc coating on said grains to produce zinc-coated free grains.
  • a process for preparing a solid permanent magnet which comprises incorporating said zinc-coated free grains of claim 1 in a non-magnetic matrix having a consistency which is sufficiently liquid to leave said zinc-coated grains in a substantially unfixed position, applying to said incorporated zinc-coated grains a magnetic field of at least 4 kilooersteds to align the grains along their easy axis of magnetization and fixing said magnetized grains in their magnetically aligned position by solidifying said non-magnetic matrix material.
  • said nonmagnetic matrix material is selected from the group consisting of plastics, elastomers, metals and wax.
  • a process for treating large grains of cobalt-samarium alloy having useful permanent magnet properties to stabilize these properties in air at elevated temperatures which comprises forming an alloy melt of cobalt and samarium wherein the samarium content ranges from about 34 to 38 percent by weight of said alloy, cooling said alloy melt at a rate sufliciently slow to produce a solid cast body wherein the cast grains have a size ranging from about microns to 1000 microns, said cast grains being single crystals grains, comminuting said solid cast body to produce free grains having a size corresponding to or smaller than the size of said cast grains, recovering said free grains ranging in size from about 50 to 200 microns with at least 85 percent by weight of said recovered free grains being single crystals free grains, annealing said free grains in an atmosphere in which they are substantially inert at a temperature ranging from 900 C.
  • the annealed recovered free grains have the property of showing at room temperature after being magnetized to at least within about 10 percent of full saturation magnetization a relative magnetization 411-I/B of at least 50 percent at a demagnetizing field of -4 kilooersteds, admixing said recovered free grains with zinc powder in an amount ranging from about 1 to about 15 percent by weight of said grains, and heating the resulting mixture at a temperature ranging from about 400 C. to 500 C. in an atmosphere in which said mixture is substantially inert to form a continuous zinc coating on said grains to produce zinc-coated free grains.
  • a process for preparing a solid permanent magnet which comprises incorporating said zinc-coated free grains of claim 6 in a non-magnetic matrix having a consistency which is sufiiciently liquid to leave said zinc-coated grains in a substantially unfixed position, applying to said incorporated grains a magnetic field of at least 4 kilooersteds to align the grains along their easyaxis of magnetization and fixing said magnetized grains in their magnetically aligned position by solidifying said non-magnetic matrix material.
  • nonmagnetic matrix material is selected from the group consisting of plastics, elastomers, metals, and wax.
  • Annealed free grains consisting essentially t cobalt-samarium alloy having substantially stable permanent magnet properties in air at elevated temperatures wherein the samarium content ranges from about 34 to 38 percent by weight of said cobalt-samarium alloy, said free grains ranging in size from about 50 microns to 200 microns with at least 85 percent by weight of said free grains being single crystal grains, said annealed free grains having a continuous coating of zinc with said zinc being present in an amount ranging from about 1 to percent by weight of said grains, said zinc-coated annealed free grains having the property of showing at room temperature after being magnetized to at least approach saturation magnetization a relative magnetization 41rJ/B of at least 50 percent at a demagnetizing field of -4 kilooersteds where 4x118 the magnetization value and B is the remanent induction.
  • Annealed free grains consisting essentially of cobaltsamarium alloy containing about percent by weight samarium, having substantially stable permanent magnet properties in air at elevated temperatures, said free grains ranging in size from about microns to microns with at least 95 percent by weight of said free grains being single crystal free grains, said annealed free grains having a continuous coating of zinc with said zinc being present in an amount ranging from about 1 to 15 percent by weight of said grains, said zinc-coated annealed free grains having the property of showing at room temperature after being magnetized to at least approach saturation magnetization a relative magnetization 41rJ/B of at least 50 References Cited UNITED STATES PATENTS 3,540,945

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  • Power Engineering (AREA)
  • Chemical & Material Sciences (AREA)
  • Crystallography & Structural Chemistry (AREA)
  • Inorganic Chemistry (AREA)
  • Hard Magnetic Materials (AREA)
  • Powder Metallurgy (AREA)
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US00244423A 1972-04-17 1972-04-17 Large grain cobalt-samarium intermetallic permanent magnet material stabilized with zinc and process Expired - Lifetime US3811962A (en)

Priority Applications (10)

Application Number Priority Date Filing Date Title
US00244423A US3811962A (en) 1972-04-17 1972-04-17 Large grain cobalt-samarium intermetallic permanent magnet material stabilized with zinc and process
GB1399873A GB1415918A (en) 1972-04-17 1973-03-22 Large grain cobalt-samarium intermetallic permanent magnet material stabilized with zinc and process
CA167,806A CA985068A (en) 1972-04-17 1973-04-03 Cobalt-samarium magnets stabilized with zinc
IT22651/73A IT982726B (it) 1972-04-17 1973-04-06 Materiale intermetallico di co balto e samario a grandi grani per magneti permanenti stabiliz zato con zinco e processo per esso
NL7304872A NL7304872A (US20020051482A1-20020502-M00057.png) 1972-04-17 1973-04-06
DE2319007A DE2319007A1 (de) 1972-04-17 1973-04-14 Intermetallisches kobalt-samarium-material fuer permanentmagnete sowie verfahren zu dessen herstellung
ES413773A ES413773A1 (es) 1972-04-17 1973-04-16 Procedimiento para tratar material magnetico permanente in-termetalico de cobalto-samario de grano grande.
JP4229973A JPS5722961B2 (US20020051482A1-20020502-M00057.png) 1972-04-17 1973-04-16
BE130048A BE798260A (fr) 1972-04-17 1973-04-16 Materiau pour aimant permanent au cobalt et au samarium stabilise au zinc
FR7313924A FR2180897B1 (US20020051482A1-20020502-M00057.png) 1972-04-17 1973-04-17

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JP (1) JPS5722961B2 (US20020051482A1-20020502-M00057.png)
BE (1) BE798260A (US20020051482A1-20020502-M00057.png)
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DE (1) DE2319007A1 (US20020051482A1-20020502-M00057.png)
ES (1) ES413773A1 (US20020051482A1-20020502-M00057.png)
FR (1) FR2180897B1 (US20020051482A1-20020502-M00057.png)
GB (1) GB1415918A (US20020051482A1-20020502-M00057.png)
IT (1) IT982726B (US20020051482A1-20020502-M00057.png)
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Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3979619A (en) * 1973-09-24 1976-09-07 Canadian General Electric Co. Ltd. Permanent magnet field structure for dynamoelectric machines
US4536233A (en) * 1980-12-16 1985-08-20 Kabushiki Kaisha Suwa Seikosha Columnar crystal permanent magnet and method of preparation
US4769130A (en) * 1982-03-12 1988-09-06 A/S Niro Atomizer High-gradient magnetic separator
US5186765A (en) * 1989-07-31 1993-02-16 Kabushiki Kaisha Toshiba Cold accumulating material and method of manufacturing the same
US20150310971A1 (en) * 2014-04-25 2015-10-29 United Technologies Corporation Magnetic material and method therefor
US10046334B2 (en) 2012-03-30 2018-08-14 Rsr Technologies, Inc. Magnetic separation of electrochemical cell materials

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS5965832U (ja) * 1982-10-25 1984-05-02 セイレイ工業株式会社 トラクタの主変速レバ−枢支部におけるジヤバラ状ブ−ツのエア−抜き孔構造

Cited By (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3979619A (en) * 1973-09-24 1976-09-07 Canadian General Electric Co. Ltd. Permanent magnet field structure for dynamoelectric machines
US4536233A (en) * 1980-12-16 1985-08-20 Kabushiki Kaisha Suwa Seikosha Columnar crystal permanent magnet and method of preparation
US4769130A (en) * 1982-03-12 1988-09-06 A/S Niro Atomizer High-gradient magnetic separator
US5186765A (en) * 1989-07-31 1993-02-16 Kabushiki Kaisha Toshiba Cold accumulating material and method of manufacturing the same
US10046334B2 (en) 2012-03-30 2018-08-14 Rsr Technologies, Inc. Magnetic separation of electrochemical cell materials
US11103880B2 (en) 2012-03-30 2021-08-31 Rsr Technologies, Inc. Magnetic separation of electrochemical cell materials
US11919010B2 (en) 2012-03-30 2024-03-05 Rsr Technologies, Inc. Magnetic separation of electrochemical cell materials
US20150310971A1 (en) * 2014-04-25 2015-10-29 United Technologies Corporation Magnetic material and method therefor

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NL7304872A (US20020051482A1-20020502-M00057.png) 1973-10-19
CA985068A (en) 1976-03-09
JPS4920694A (US20020051482A1-20020502-M00057.png) 1974-02-23
ES413773A1 (es) 1976-01-16
JPS5722961B2 (US20020051482A1-20020502-M00057.png) 1982-05-15
FR2180897A1 (US20020051482A1-20020502-M00057.png) 1973-11-30
DE2319007A1 (de) 1973-11-08
IT982726B (it) 1974-10-21
FR2180897B1 (US20020051482A1-20020502-M00057.png) 1978-11-03
BE798260A (fr) 1973-08-16
GB1415918A (en) 1975-12-03

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