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
  • C22C38/10—Ferrous alloys, e.g. steel alloys containing cobalt
  • C22C38/105—Ferrous alloys, e.g. steel alloys containing cobalt containing Co and Ni
• • 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

Definitions

• the invention relates to a method of manufacturing anisotropic permanent magnets of an alloy on the basis of Co, Ni, Al, Ti and Fe, in which a magnet body is quenched to below the Curie temperature, and then exposed to a magnetic field for some time in a temperature range of 10 C. to 70 C. below the Curie temperature.
• a magnet body is formed by the solidification of a homogeneous melt of the alloy concerned.
• the magnet body is formed as a homogeneous mixed-crystal having a cubic space-centered lattice, the so-called a-phase. If cooling is performed down from said u-phase without special precautions being taken, the aphase will partly change into the 'y-phase, which is cubic, plane-centered. This y-phase is very harmful to the magnetic properties.
• the formation of this 'y-phase may, however, be prevented by quenching the body from a temperature above 1200 C. to below about 900 C. Below this value of about 900 C.
• a temperature is found at which the a-phase changes partly into a diiferent phase (04'- phase), which is also cubic, space-centered.
• the temperature at which said separation of the u-phase into the (a-l-u')-phase takes place in general, substantially coincides with the Curie temperature of the alloy concerned.
• the invention is based on the experimentally acquired recognition that no -phase is found in the alloys of the group mentioned in said patent specification, which have a sufliciently high Al-content and a sufficiently high Ticontent, when cooled from the state of the homogeneous melt down to the point of separation of the a-phase into (a-i-a), even when cooled across said temperature range instead of being quenched.
• a more important consequence is, however, that such permanent magnets can now be manufactured directly from the solidified alloy without the need for previous homogenization above 1200 C.
• the point of separation is higher (for example, C. higher) than the Curie point.
• the thermal treatment in the magnetic field known from said patent specification cannot be directly carried out.
• the magnet body must first be quenched to below the Curie point.
• the smaller temperature range for example, C.
• the lower temperature of quenching the quenching process can be carried out in a much simpler manner than the quenching process known from said patent specification.
• This advantage becomes particularly manifest when the bodies to be quenched are comparatively large; since the temperature range according to the invention can be covered more rapidly, the magnetic properties are, in general, better.
• the method according to the invention is characterized in that the magnet body of an alloy having 28 to 45% of Co, 10 to 20% of Ni, 7 to 9% of Al, 7 to 10% of Ti, up to 6% of Cu and otherwise mainly Fe is quenched from a temperature lying between 900 C. and 1000 C.
• the value of said temperature between 900 C. and 1000 C. depends upon the alloy selected, that is to say, mainly upon the Aland Ti-contents.
• the process is much simpler and hence more economical than the process hitherto known, but also, as stated above, the magnetic properties appear to be considerably improved.
• the latter is due to the fact that quenching can be performed at a higher rate, which is particularly important in quenching comparatively large bodies.
• the magnets made from the alloys 1 and 2 are known from Cobalt N0. 34, March 1967, page 16 (French edition) and from the US. patent specification 2,837,452 respectively.
• the magnets made from the alloys 3 and 4 are manufactured by the method according to the in- 5 What is claimed is:
• a method of manufacturing anisotropic permanent magnets comprising the steps of forming a ferrous alloy consisting of about 28 to 45% of Co, 10 to 20% of Ni, 7 to 9% of Al, 7 to 10% of Ti, up to 6% of Cu and the balance principally iron, quenching said alloy only
• the magnets made from the alloys 5, 6 and 7 are known from Proceedings of the International Conference on Magnetism, Nottingham, September 1964, pages 767 ff., the French Pat. No. 1,493,293 and the French 20 Pat. No. 1,482,702.
• the magnet of the alloy 8 is made by the method according to the invention.

Landscapes

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

Applications Claiming Priority (1)

Publications (1)

Family

ID=19800401

Family Applications (1)

Country Status (10)

Cited By (2)

Families Citing this family (1)

• 1967
  • 1967-06-09 NL NL6708112.A patent/NL154036C/xx active
• 1968
  • 1968-05-13 US US728751A patent/US3598662A/en not_active Expired - Lifetime
  • 1968-06-06 DK DK265268AA patent/DK120352B/da unknown
  • 1968-06-06 AT AT540568A patent/AT318684B/de active
  • 1968-06-06 CH CH847268A patent/CH495611A/de not_active IP Right Cessation
  • 1968-06-06 SE SE07628/68A patent/SE339729B/xx unknown
  • 1968-06-07 FR FR1567847D patent/FR1567847A/fr not_active Expired
  • 1968-06-07 ES ES354769A patent/ES354769A1/es not_active Expired
  • 1968-06-07 GB GB27169/68A patent/GB1171892A/en not_active Expired
  • 1968-06-07 BE BE716284D patent/BE716284A/xx unknown

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