Crucible Materials Corporation

Ybm Magnex International, Inc.

Andrew S Kim

Floyd E Camp

Edward J Dulis

A rare earth element containing permanent magnet which retains its magnetic properties at elevated temperatures by a combination of reducing the temperature coefficient of intrinsic coercivity lower than -0.2%/.degree.C., and increasing the intrinsic coercivity to over 10 kO.sub.e.

Temperature stable permanent magnet

A permanent magnet alloy and method for production thereof. The permanent magnet alloy has a rare earth element including Nd, B, Fe, C, and oxygen, with additions of Co and at least one of Cu, Ga and Ag. The alloy may be produced by contacting particles thereof with carbon- and oxygen-containing material to achieve desired carbon and oxygen contents.

RE-Fe-B magnets and manufacturing method for the same

Re-Fe-B magnets and manufacturing method for the same

A permanent magnet of the neodymium-iron-boron type having improved corrosion resistance imparted by a combination of oxygen, carbon and nitrogen. Oxygen is provided in an amount equal to or greater than 0.6 weight percent in combination with carbon of 0.05-0.15 weight percent and nitrogen 0.15 weight percent maximum. Preferably, oxygen is within the range of 0.6-1.2% with carbon of 0.05-0.1% and nitrogen 0.02-0.15 weight percent or more preferably 0.04-0.08 weight percent. The magnet may be heated in an argon atmosphere and thereafter quenched in an atmosphere of either argon or nitrogen to further improve the corrosion resistance of the magnet.

Permanent magnet having improved corrosion resistance and method for

A method for improving the magnetic properties, particulaarly intrinsic coercivity, of particles of a permanent magnet alloy comprising a rare earth element, iron and boron. The method includes subjecting particles to a hydrogen atmosphere for a time at elevated temperature sufficient to hydride the particles. The hydrogen atmosphere is removed while maintaining the particles at the elevated temperature. Thereafter, while maintaining the particles at elevated temperature, the particles are subjected to a vacuum atmosphere for a time at the maintained elevated temperature sufficient to dehydride the particles. Thereafter, while maintaining the particles at the elevated temperature, they are again subjected to a hydrogen atmosphere for a time at the maintained elevated temperature sufficient to hydride the particles. The hydrogen atmosphere is removed while maintaining the particles at the elevated temperature. Thereafter, the particles are subjected to a vacuum atmosphere for a time at the maintained elevated temperature sufficient to dehydride the particles. The dehydrided particles are then cooled to room temperature.

Method for producing rare earth magnet particles of improved coercivity

A method for making rare earth element, iron and boron sintered permanent magnets, and a particle mixture for use therein. A hydrided 100% dross or particle mixture of virgin alloy particles and scrap alloy particles and/or dross alloy particles are dehydrided and sintered to produce a substantially fully dense article for use as a permanent magnet.

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Pittsburgh, PA, United States of America

Andrew S Kim