Classifications

• • 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
  • B22F3/12—Both compacting and sintering
• • C—CHEMISTRY; METALLURGY
  • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
  • C22C—ALLOYS
  • C22C1/00—Making non-ferrous alloys
  • C22C1/04—Making non-ferrous alloys by powder metallurgy
  • C22C1/0433—Nickel- or cobalt-based alloys
  • C22C1/0441—Alloys based on intermetallic compounds of the type rare earth - Co, Ni
• • C—CHEMISTRY; METALLURGY
  • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
  • C22C—ALLOYS
  • C22C19/00—Alloys based on nickel or cobalt
  • C22C19/07—Alloys based on nickel or cobalt based on cobalt
• • 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
• • 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
  • H01F1/0555—Alloys characterised by their composition containing rare earth metals and magnetic transition metals, e.g. SmCo5 pressed, sintered or bonded together
  • H01F1/0557—Alloys characterised by their composition containing rare earth metals and magnetic transition metals, e.g. SmCo5 pressed, sintered or bonded together sintered

Definitions

• the invention relates to a method of manufacturing a body having anisotropic, permanent magnetic properties, the constituent essential to said properties being a compound having a hexagonal crystal structure, the existence range of which forms one assembly with the existence range of the compound M R occurring in the system M-R, where M is Co or a combination of Co with one or more of the elements Fe, Ni and Cu, and R is one or more of the elements of the rare earths and/or Th, by sintering a powder which consists of a compound of M and R.
• the element Y is deemed to be included in the elements of the rare earths.
• the resulting magnetic body is magnetically anisotropic when the powder particles, before being sintered, are oriented in a magnetic field.
• the sintering method has a few advantages.
• the sintering method is much more economic for series production of M R magnets: no heavy press is needed, for example.
• the coercive force of the sintered M R magnets is considerably higher than that of compressed M R magnets having the same M and R.
• the coercive force of a sintered M R magnet may be approximately constant whereas that of a compressed M R magnet decreases reduces as a function of timethe so-called ageing.
• the retentivity B, measured at the sintered body was found to be comparatively low, namely approximately 6000 G.
• a lower B results in a lower energy product (BH) of the ultimate permanent magnet.
• known methods can be used with which the formation of Sm O during sintering is prevented. This can be carried out, for example, by grinding the starting mixture under dried toluene in order to obtain an anhydrous powder. This may be done alternatively by annealing the powder, possibly in the presence of an oxygen getter, for example, Ca, so as to remove the oxygen therefrom. Said known methods turned out to give unsatisfactory results. The desirable result is obtained indeed when the castings from which was startedif desirable, after first having coarsely ground them-were pulverized in an atmosphere protecting against oxidation, for example, in a rare gas atmosphere, in which at most ppm.
• the method according to the invention is characterized in that first castings are manufactured, at least one having an atomic ratio M:R 5 and one having an atomic ratio M:R 5, which are pulverized and mixed in an atmosphere protecting against oxidation and containing more than 100 ppm. of oxygen and/or water vapour,
• said powder is then oriented in a magnetic field, compressed and sintered between 800 C.-1250 C.
• Essential to the invention thus is that grinding, orientation, compression and sintering is carried out in an atmosphere which is poor in oxygen and water vapour while the starting material does not consist of one compound but of at least two compounds in such a ratio that finally after sintering the desired M R compound is obtained.
• a preferred embodiment of the method according to the invention is characterized in that both the powder of the atomic ratio M:R 5 and that of the atomic ratio M:R 5 can readily be oriented in a magnetic field.
• a further preferred embodiment of the method according to the invention is characterized in that the atmosphere protecting against oxidation contains less than 5 p.p.m. of oxygen and/ or water vapour.
• the invention furthermore comprises bodies having anisotropic, permanent magnetic properties manufactured by any of the above-mentioned methods.
• the castings are coarsely ground. Of these coarsely ground fractions, 3.0 gms. of SmCo and 1.5 gms. of Sm CQ were ground in a mortar until the average diameter of the particles was less than 30a. The grinding process in the mortar took place in a so-called glove box in which an Ar atmosphere prevailed which contained approximately 1 p.p.m. of oxygen and approximately 1 p.p.m. of water vapour.
• the measured magnetic values of the permanent magnet were:
• each of oxygen and water vapour in proportions forming a powder which after sintering forms a body consisting essentially of the compound M R, orienting said powder in a magnetic field while in said atmosphere, and thereafter compacting and sintering said powder between 800 C. and 1250 C. to form said body.
• the starting powder consists of a mixture of Sm Co and SmCo 5 DEWAYNE RUTLEDGE, Primary Examiner References Cited G. K. WHITE, Assistant Examiner UNITED STATES PATENTS U.S. Cl. X.R.

Landscapes

• Chemical & Material Sciences (AREA)
• Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• Power Engineering (AREA)
• Metallurgy (AREA)
• Organic Chemistry (AREA)
• Crystallography & Structural Chemistry (AREA)
• Inorganic Chemistry (AREA)
• Materials Engineering (AREA)
• Manufacturing & Machinery (AREA)
• Hard Magnetic Materials (AREA)
• Powder Metallurgy (AREA)
• Manufacturing Cores, Coils, And Magnets (AREA)

Applications Claiming Priority (1)

Publications (1)

Family

ID=19807953

Family Applications (1)

Country Status (11)

Cited By (17)

Families Citing this family (4)

• 0
  • BE BE756431D patent/BE756431A/fr unknown
• 1969
  • 1969-09-20 NL NL6914311A patent/NL6914311A/xx unknown
• 1970
  • 1970-08-29 DE DE19702043000 patent/DE2043000A1/de active Pending
  • 1970-09-03 AU AU19557/70A patent/AU1955770A/en not_active Expired
  • 1970-09-11 US US00071376A patent/US3723197A/en not_active Expired - Lifetime
  • 1970-09-17 AT AT841370A patent/AT301891B/de not_active IP Right Cessation
  • 1970-09-17 CH CH1381770A patent/CH544387A/de not_active IP Right Cessation
  • 1970-09-17 GB GB44504/70A patent/GB1298977A/en not_active Expired
  • 1970-09-17 JP JP45080967A patent/JPS4913132B1/ja active Pending
  • 1970-09-18 ES ES383757A patent/ES383757A1/es not_active Expired
  • 1970-09-21 FR FR7034136A patent/FR2064818A5/fr not_active Expired

Also Published As

Similar Documents