Gm Global Technolgoy Operations, Inc.

Marko Materials, Inc.

Magnequench International, Inc.

Magnequench Limited

Other

Mbs Engineering, LLC

Viswanathan Panchanathan

Ranjan Ray

Bill C Giessen

John J Croat

Stanley Byron Musselman

Mitchell L Spencer

William Ray Green

Gregory P Meisner

Barry Hal Rabin

Norio Yoshikawa

Yasuaki Kasai

Kevin Young

Yutaka Yoshida

Kevin A Young

Teruo Watanabe

Charles Howard Sellers

John E Mason

Joseph James Worden

Wilhelm Ervens

Edward E Welker

Robert Eugene Dickey

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.

Magnet and holder assembly having improved rotational and axial stability

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.

Magnet rotor assembly including a vacuum impregnated bonded magnet having increased crush strength at high temperatures

The invention relates to magnets, particularly bonded magnets, of the Re&mdash;Fe&mdash;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. As compared to bonded magnets made from melt-spun powders or from other conventional atomized powders, bonded magnets of the present invention exhibit one or more of the following properties: less loss of intrinsic coercivity under repeated injection molding cycles; less internal magnetic shearing loss; improved flowability of the magnetic powders; improved Br and part integrity; less environmental degradation after exposure to high temperature and less flux loss; complex shapes and high part integrity; lower viscosity of the magnetic powder-binder mixtures; and high magnetic strength even for small-dimension magnets.

Bonded magnets made with atomized permanent magnetic powders

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.

Isotropic rare earth material of high intrinsic induction

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.

Cu additions to Nd-Fe-B alloys to reduce oxygen content in the ingot and rapidly solidified ribbon

Permanent rare-earth magnets containing Ce are fabricated with coercivity greater than 4 kOe. One composition for such magnets is &lsqb;Ce,R,&rsqb;,(F,B,),, where R is one or more rare-earth elements, F is Fe or Fe&mdash;Co, and the relative elemental atomic composition is 0.0<y&lE;0.3, 0.04&lE;z&lE;0.25, and 0.01&lE;v&lE;0.30. Another composition is &lsqb;(Ce,La,),R,&rsqb;,(F,B,),, with the relative elemental atomic composition x<0.4 or 0.9<x&lE;1.0 and 0.2&lE;y&lE;0.8, 0.04&lE;z&lE;0.25, and 0.01&lE;v&lE;0.30.

Rare-earth iron-boron magnet containing cerium and lanthanum

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.

Rare-earth alloy powders for magnets and process for making magnets from

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.

Bonded Nd-Fe-B magnets without volumetric expansion defects

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.

Bonded magnet made from gas atomized powders of rare earth alloy

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.

Bonded magnet with low losses and easy saturation

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.

High remanence hot pressed magnets

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.

Fabrication of permanent magnets without loss in magnetic properties

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.

Hot pressed magnets formed from anisotropic powders

A method is disclosed for producing a rapidly solidified, fine grained, magnetically anisotropic powder of the RE-Fe-B type. The rapidly solidified material is optimally quenched or slightly overquenched and is subjected to a hydrogen absorption-hydrogen desorption process that produces a fine grained material containing the essential magnetic phase RE.sub.2 TM.sub.14 B and an intergranular phase and is magnetically anisotropic.

Growing community of inventors

Anderson, IN, United States of America

Viswanathan Panchanathan