A field magnet manufacturing method where a bonded magnet's inner surface press-fitted in a yoke has a certain accuracy irrespective of the accuracy of the yoke's outer circumferential surface. A cylindrical bonded magnet from binding magnet particles with a thermosetting resin is fixed in a tubular yoke of magnetic material. The method includes reheating and softening the bonded magnet after thermal curing; and press-fitting in the bonded magnet after the softening step from a tapered portion on one end side of the yoke to press the bonded magnet's outer circumferential surface against the yoke's inner surface. The press-fitting includes feeding the bonded magnet relatively into the yoke while allowing a relative posture variation between the bonded magnet and the yoke so the bonded magnet's inner surface to be remolded into a shape along the inner surface of the yoke exhibits almost the same accuracy as the yoke's inner surface.

The present invention provides a method for manufacturing a conductive film, comprising the steps of: applying, to a substrate, a conductive paste dispersed in an organic material and comprising metal particles and Fe—B—Cu—C alloy magnetic heating element particles; and selectively sintering the applied conductive paste by means of induction heating so as to form a conductive film, wherein the magnetic heating element particles are implemented with crystallized Fe—B—Cu—C alloy particles. Therefore, it is possible to selectively form a conductive adhesive layer by sintering through induction heating. In addition, it is possible to produce an adhesive capable of low-temperature bonding by forming a magnetic heating element having crystal grains with a large coercive force through heat treatment after formation of an alloy.

A permanent magnet alloy according to the present disclosure contains Mn at a content not lower than 41% by atom and not higher than 53% by atom; Al at a content not lower than 46% by atom and not higher than 53% by atom; and Cu at a content not lower than 0.5% by atom and not higher than 10% by atom. The alloy contains a stable phase, having a tetragonal structure, at a ratio not lower than 50%.

Techniques are disclosed for milling an iron-containing raw material in the presence of a nitrogen source to generate anisotropically shaped particles that include iron nitride and have an aspect ratio of at least 1.4. Techniques for nitridizing an anisotropic particle including iron, and annealing an anisotropic particle including iron nitride to form at least one α″-Fe.sub.16N.sub.2 phase domain within the anisotropic particle including iron nitride also are disclosed. In addition, techniques for aligning and joining anisotropic particles to form a bulk material including iron nitride, such as a bulk permanent magnet including at least one α″-Fe.sub.16N.sub.2 phase domain, are described. Milling apparatuses utilizing elongated bars, an electric field, and a magnetic field also are disclosed.

Improved manufacturing processes and resulting anisotropic permanent magnets, such as for example alnico permanent magnets, having highly controlled and aligned microstructure in the solid state are provided. A certain process embodiment involves applying a particular orientation and strength of magnetic field to loose, binder-coated magnet alloy powder particles in a compact-forming device as they are being formed into a compact in order to preferentially align the magnet alloy powder particles in the compact. The preferential alignment of the magnet alloy powder particle is locked in place in the compact by the binder after compact forming is complete. After removal from the device, the compact can be subjected to a subsequent sintering or other heat treating operation.

A rotating electric machine according to embodiments is a rotating electric machine including a rotor including a first core and being capable of rotating around a rotating shaft; and a stator disposed to face the rotor in the axial direction of the rotating shaft, the first core including a first pressed powder material having a plurality of first flaky magnetic metal particles and a first intercalated phase, the first flaky magnetic metal particles having an average thickness of from 10 nm to 100 μm, each first flaky magnetic metal particle having a first flat surface and a first magnetic metal phase including at least one first element selected from the group consisting of Fe, Co, and Ni, the average value of the ratio of the average length in the first flat surface with respect to the average thickness being from 5 to 10,000, the first intercalated phase existing between the first flaky magnetic metal particles and including at least one second element selected from the group consisting of oxygen (O), carbon (C), nitrogen (N), and fluorine (F), wherein in the first pressed powder material, the first flat surfaces are oriented approximately in parallel with a first principal plane of the first pressed powder material and have the difference in magnetic permeability on the basis of direction within the first principal plane, and the first principal plane of the first pressed powder material is disposed to be approximately perpendicular to the radial direction of the rotating electric machine.

A rotating electric machine according to embodiments is a rotating electric machine including a rotor including a first core and being capable of rotating around a rotating shaft; and a stator disposed to face the rotor in the axial direction of the rotating shaft, the first core including a first pressed powder material having a plurality of first flaky magnetic metal particles and a first intercalated phase, the first flaky magnetic metal particles having an average thickness of from 10 nm to 100 μm, each first flaky magnetic metal particle having a first flat surface and a first magnetic metal phase including at least one first element selected from the group consisting of Fe, Co, and Ni, the average value of the ratio of the average length in the first flat surface with respect to the average thickness being from 5 to 10,000, the first intercalated phase existing between the first flaky magnetic metal particles and including at least one second element selected from the group consisting of oxygen (O), carbon (C), nitrogen (N), and fluorine (F), wherein in the first pressed powder material, the first flat surfaces are oriented approximately in parallel with a first principal plane of the first pressed powder material and have the difference in magnetic permeability on the basis of direction within the first principal plane, and the first principal plane of the first pressed powder material is disposed to be approximately perpendicular to the radial direction of the rotating electric machine.

A method for continuous manufacture of permanent magnets. A material sheet is formed into an open tube, having a lengthwise opening. Magnetic powder may be poured into the lengthwise opening on a continuous basis. The tube opening is then formed closed and sealed. The magnetic powder is magnetically pre-aligned by subjecting it to a first magnetic field. The tube containing the powder may be compressed into a desired shape, forming an elongated permanent magnet. After compression, the elongated magnet is magnetized by a second magnetic field in two-step process, wherein the elongated permanent magnet is subjected to a magnetic field from first magnetizing coil that is pulsed with a first electric current in a first direction, followed by a second magnetizing coil being pulsed with a second magnetizing electric current in a second direction. The elongated magnet may be formed into any arbitrary shape, such as a ring or coil.

A ferrite sintered magnet 100 comprises M-type ferrite crystal grains 4 and multiple-crystal grain boundaries 6b surrounded by three or more of the M-type ferrite crystal grains 4. The ferrite sintered magnet 100 contains at least Fe, Ca, B, and Si, and contains 0.005 to 0.9 mass % of B in terms of B.sub.2O.sub.3. The multiple-crystal grain boundaries 6b contain Si and Ca, and in a case where the molar ratio of Ca to Si in the multiple-crystal grain boundaries 6b is represented by (Ca/Si).sub.G, the following formula is satisfied.
0.1<(Ca/Si).sub.G<0.9

Improved manufacturing processes and resulting anisotropic permanent magnets, such as for example alnico permanent magnets, having highly controlled and aligned microstructure in the solid state are provided. A certain process embodiment involves applying a particular orientation and strength of magnetic field to loose, binder-coated magnet alloy powder particles in a compact-forming device as they are being formed into a compact in order to preferentially align the magnet alloy powder particles in the compact. The preferential alignment of the magnet alloy powder particle is locked in place in the compact by the binder after compact forming is complete. After removal from the device, the compact can be subjected to a subsequent sintering or other heat treating operation.