Abstract: A magnet held in a magnet holder is constrained against radial or axial instability, or against both, by a shape on either component in contact with complementary shape on the other component, the shaped components generally defining a tab-and-slot arrangement. The magnet component may be a bonded magnet and in one embodiment may be formed in place by injection molding. The magnet also will exhibit improved magnet properties when magnetized to have lines of polarity matching a path defined by the bulk of the magnetic material as governed by the location of tabs on the magnet. The invention is useful in magnet-sensor assemblies found in industrial applications and in automotive applications such as power steering systems.

Abstract: A magnet rotor assembly comprises a magnet sleeve held on a rotor shaft by a rigid adhesive layer that includes at least one axial wedge shape corresponding to an axial irregularity on at least one of the surfaces bonded by the adhesive layer. Improved crush strength in the magnet sleeve and in other bonded metal parts, both initially and after exposure to high temperatures is accomplished by impregnating the parts with a curable resin.

Abstract: A method for making a magnet rotor assembly part by providing a bonded metal part having a determinable crush strength, impregnating the bonded metal part with a curable resin and curing the resin so that the crush strength of the assembly part is increased above the determinable crush strength both initially and after extended exposure to temperatures of at least 160° C. Improved crush strength in the magnet sleeve and in other bonded metal parts, both initially and after exposure to high temperatures is accomplished by impregnating the parts with a curable resin.

Abstract: A magnet held in a magnet holder is constrained against radial or axial instability, or against both, by a shape on either component in contact with complementary shape on the other component, the shaped components generally defining a tab-and-slot arrangement. The magnet component may be a bonded magnet and in one embodiment may be formed in place by injection molding. The magnet also will exhibit improved magnet properties when magnetized to have lines of polarity matching a path defined by the bulk of the magnetic material as governed by the location of tabs on the magnet. The invention is useful in magnet-sensor assemblies found in industrial applications and in automotive applications such as power steering systems.

Abstract: A magnet rotor assembly comprises a magnet sleeve held on a rotor shaft by a rigid adhesive layer that includes at least one axial wedge shape corresponding to an axial irregularity on at least one of the surfaces bonded by the adhesive layer. Improved crush strength in the magnet sleeve and in other bonded metal parts, both initially and after exposure to high temperatures is accomplished by impregnating the parts with a curable resin.

Abstract: Improved resin-bonded powdered metal components are protected against corrosion and reduction of crush strength during contact with corrosive fluids such as alcohols, ethanol-containing fuels, glycols and peroxide-containing fuels by a resin system coating that, when cured, provides a relatively high crosslink density and relatively few hydrolysable radicals. Magnetic properties of resin-bonded powdered metal magnets are protected from heat degradation by the cured resin coating. The coating can be a heat-cured resin system comprising a phenol novolac resin and a compatible hardener. In one embodiment magnetizable powdered materials have an uncured resin system coating to provide a B-stage material that can be cured after compression shaping.

Abstract: The invention relates to magnets, particularly bonded magnets, of the Re—Fe—B type made from atomized magnetic powders and to methods of producing the powders and the magnet. The magnetic powders comprise, by weight, about 15% to 25% of RE; about 0.8% to 2.0% of B; about 1% to 10% of T; and balanced with Fe, Co, or mixtures thereof; wherein RE is one or more rare earth elements selected from the group consisting of Y, La, Ce, Pr, Nd, Sm, Er, Gd, Tb, Dy, Ho, Tm, Yb and Lu, and T is one or more elements selected from the group consisting of Ti, Zr, Hf, V, Nb, Ta, Cr, Mo, and W. To produce bonded magnets, the atomized powders are heat treated, combined with a binder, pressed or molded, and cured to produce the bonded magnets.

Abstract: Isotropic magnetic alloy powder having an intrinsic magnetic induction of at least two third of its magnetic remanence and method for making same are provided. The powder is made from an alloy having a composition comprising, by weight percentage, approximately 15 to 35 percent of one or more rare earth metals, approximately 0.5 to 4.5 percent of boron, and approximately 0 to 20 percent of cobalt, balanced with iron. The alloy powder is made by a process wherein an amount of the alloy is melt and spun in an inert environment, preferably at a distance between an orifice and a wheel being less than one and one half inches, into ribbons, followed by crushing the ribbons into powder and annealing the powder.

Abstract: The invention relates to magnets, particularly bonded magnets, of the Re—Fe—B type made from atomized magnetic powders and to methods of producing the powders and the magnet. The magnetic powders comprise, by weight, about 15% to 25% of RE; about 0.8% to 2.0% of B; about 1% to 10% of T; and balanced with Fe, Co, or mixtures thereof; wherein RE is one or more rare earth elements selected from the group consisting of Y, La, Ce, Pr, Nd, Sm, Er, Gd, Tb, Dy, Ho, Tm, Yb and Lu, and T is one or more elements selected from the group consisting of Ti, Zr, Hf, V, Nb, Ta, Cr, Mo, and W. To produce bonded magnets, the atomized powders are heat treated, combined with a binder, pressed or molded, and cured to produce the bonded magnets.

Abstract: Isotropic magnetic alloy powder having an intrinsic magnetic induction of at least two third of its magnetic remanence and method for making same are provided. The powder is made from an alloy having a composition comprising, by weight percentage, approximately 15 to 35 percent of one or more rare earth metals, approximately 0.5 to 4.5 percent of boron, and approximately 0 to 20 percent of cobalt, balanced with iron. The alloy powder is made by a process wherein an amount of the alloy is melt and spun in an inert environment, preferably at a distance between an orifice and a wheel being less than one and one half inches, into ribbons, followed by crushing the ribbons into powder and annealing the powder.

Abstract: A process is disclosed for producing rare earth-iron-boron alloys and magnets with reduced oxygen content and improved yield. Such a reduction in oxygen content and improvement in yield are achieved by including copper in a melt having a composition comprising a rare earth, boron, and iron, and subsequently solidifying the melt.

Abstract: Permanent rare-earth magnets containing Ce are fabricated with coercivity greater than 4 kOe. One composition for such magnets is [CeyR1−y]z(F1−vBv)1−z, where R is one or more rare-earth elements, F is Fe or Fe—Co, and the relative elemental atomic composition is 0.0<y≦0.3, 0.04≦z≦0.25, and 0.01≦v≦0.30. Another composition is [(CexLa1−x)yR1−y]z(F1−vBv)1−z, with the relative elemental atomic composition x<0.4 or 0.9<x≦1.0 and 0.2≦y≦0.8, 0.04≦z≦0.25, and 0.01≦v≦0.30.

Abstract: Isotropic magnetic alloy powder having an intrinsic magnetic induction of at least two third of its magnetic remanence and method for making same are provided. The powder is made from an alloy having a composition comprising, by weight percentage, approximately 15 to 35 percent of one or more rare earth metals, approximately 0.5 to 4.5 percent of boron, and approximately 0 to 20 percent of cobalt, balanced with iron. The alloy powder is made by a process wherein an amount of the alloy is melt and spun in an inert environment, preferably at a distance between an orifice and a wheel being less than one and one half inches, into ribbons, followed by crushing the ribbons into powder and annealing the powder.

Abstract: A process for passivating rare-earth alloy powders such that magnets formed from the powders have fewer expansion defects is described. By exposing the rare-earth alloy powders to a humid atmosphere, rare-earth oxide impurities that could result in eruptions in the magnets are reduced. Magnets made from the passivated powder show fewer expansion defects than magnets made from unpassivated powder.

Abstract: A rare earth-iron-boron magnetic composition containing a rare earth fluoride compound in a sufficient amount to reduce or eliminate the formation of rare earth hydroxide and a method of making the same. The reduction or elimination of the formation of rare earth hydroxide substantially eliminates or significantly reduces eruptions in bonded magnets caused by volumetric expansion defects.

Abstract: Bonded magnets made from gas atomized powders of an rare earth alloy and having good hard magnetic characteristics are provided. The powders have an alloy composition comprising approximately 15 to 34 weight % of RE, 0.8 to 1.2 weight % of B, 0.5 to 4 weight % of TiC, balanced with at least one of Fe and Co, wherein RE is one or more rare earth elements selected from the group consisting of Y, La, Ce, Pr, Nd, Sm, Er, Gd, Tb, Dy, Ho, Er, Tm, Yb and Lu.

Abstract: The present invention provides a bonded isotropic magnet containing a composition comprising from about 5 to 25% rare earth metal, from about 0.5 to about 4.5% boron, from about 0.5 to about 3.0% niobium, and the balance principally of iron. Such a magnet exhibits low coercivity and low loss upon aging.

Abstract: Isotropic hot pressed iron-rare earth metal permanent magnets are provided wherein the hot pressed permanent magnet exhibits magnetic remanences of at least about 9 kG, and most typically about 10 kG. Preferred compositions include a relatively low rare earth content coupled with an optimal amount of boron. The preferred composition is, on a weight percent basis, from about 5 to about 25 percent rare earth, most preferably about 10 to about 20 percent rare earth, from about 0.5 to about 4.5 percent boron, most preferably from about 0.8 to about 4.0 percent boron, wherein the total combination of the rare earths and boron ranges from about 9 percent to about 26 percent, most preferably from about 12 percent to about 22 percent, and optionally from about 2 percent to about 16 percent cobalt, with the balance being essentially iron.

Abstract: A method is provided for forming high coercivity permanent magnets from a rare earth-iron-boron metal, wherein the permanent magnets exhibit high intrinsic coercivity comparable to that of the rare earth-iron-boron metal alloy when formed by machining and appropriately heat treating the metal alloy in air at a temperature greater than the Curie temperature of the material, prior to or after the machining operation. As a result, high coercivity permanent magnets can be selectively sized and shaped to satisfy specific design requirements, without requiring that a punch and die be specially designed and manufactured to produce the permanent magnets. The heat treatment method is able to promote machinability of the metal alloy without substantially causing a loss in magnetic properties. Alternatively, the heat treatment method can be employed to substantially restore the magnetic properties of a permanent magnet which were previously reduced by conventional annealing practices.

Abstract: A method is provided for forming a high energy product, anisotropic, hot pressed iron-rare earth metal permanent magnet without the requirement for magnetic alignment during pressing or additional hot working steps. The method of this invention includes providing a quantity of anisotropic iron-rare earth metal particles and hot pressing the particles so as to form a substantially anisotropic permanent magnet. The pressed permanent magnet of this invention permits a greater variety of shapes as compared to conventional hot worked anisotropic permanent magnets. As a result, the magnetic properties and shape of the permanent magnet of this invention can be tailored to meet the particular needs of a given application.