摘要:
The permanet magnet composed of a rare earth element, e.g. samarium, and cobalt together with iron, copper and some other additive elements and prepared according to the inventive method has a high coercive force and excellent squareness of the magnetic hysteresis loop despite the relatively low content of copper which has been considered to be indispensable for obtaining a high coercive force. The characteristic feature of the inventive method consists in the aging treatment of the sintered body of the alloy powder of a specified composition undertaken in two or more steps, each being carried out by continuously cooling the sintered body within a specified temperature range at a specified cooling velocity.
摘要:
Method of preparing an anisotropic permanent magnet by a powder metallurgical technique, in which, the step of orientation of anisotropically magnetic particles during shaping by compression to give a green body prior to sintering, the magnetic field is applied pulse-wise to the mass of magnetic particles and an impacting compressive force is applied to the thus oriented particles in the direction parallel to the magnetic field during the period in which a pulse of the pulse-wise magnetic field is sustained. This method ensures a much higher degree of particle orientation than in the conventional static-field method by virtue of the possibility of obtaining a much stronger magnetic field without problems which otherwise are unavoidable. The principle of the method is applicable to the preparation of a cylindrical or annular permanent magnet magnetizable in a plurality of radial directions.
摘要:
The magnetic properties or, in particular, coercive force of a sintered permanent magnet composed of a light rare earth element, boron and iron can be greatly improved without affecting the residual magnetic flux by the admixture of a relatively small amount of additive elements including heavy rare earth elements, aluminum, titanium, vanadium, niobium and molybdenum. In the inventive magnets, the distribution of the additive element is not uniform but localized in the vicinity of the grain boundaries of the matrix particles. Such a localized distribution of the additive elements is obtain by sintering a powder mixture composed of a powder of an alloy of the base ingredients and a powder containing the additive element or elements.
摘要:
The invention provides a rare earth metal-containing alloy for permanent magnets having a composition expressed by the formulaSm.sub.1-.alpha. Ce.sub..alpha. (Co.sub.1-x-y-u-v-w Fe.sub.x Cu.sub.y Ti.sub.u Zr.sub.v Mn.sub.w).sub.z,in which the suffixes are each a numerical value as defined by:0.1.ltoreq..alpha..ltoreq.0.90;0.10.ltoreq.x.ltoreq.0.30;0.05.ltoreq.y.ltoreq.0.15;0.002.ltoreq.u.ltoreq.0.03;0.002.ltoreq.v.ltoreq.0.03;0.005.ltoreq.w.ltoreq.0.08;with the proviso that 0.01.ltoreq.u+v+w.ltoreq.0.10; and 5.7.ltoreq.z.ltoreq.8.1 . The permanent magnets prepared with the alloy have very high magnetic properties, especially, in the coercive force and the maximum energy product even better than those obtained with a samarium-based alloy along with good machinability as in the cerium-based alloys suitable for mass production.
摘要:
Disclosed is a method for the preparation of a novel composite rare earth-based magnetically anisotropic sintered permanent magnet in which: (a) a base alloy consisting of a host phase of R.sub.2 T.sub.14 B (R: a rare earth element; T: iron or a combination of iron and cobalt) having a particle diameter of 2 to 10 .mu.m and containing in each particle a phase rich in the content of T and having a particle diameter not exceeding 1 .mu.m is prepared by the strip casting method; (b) the base alloy is crushed; (c) the base alloy powder is blended in a specified proportion with a powder of an auxiliary alloy of R-T or R-T-B in a specified proportion; (d) the powder blend is subjected to further comminution; (e) the comminuted powder blend is subjected to compression-molding in a magnetic field into a powder compact; and (f) the powder compact is sintered by a heat treatment.
摘要:
A rare earth permanent magnet of the formulaR(Fe.sub.1-x-y Co.sub.x M.sub.y).sub.z,in which R is rare earth element(s) and/or Y, M is Si, Ti, Mo, B, W, V, Cr, Mn, Al, Nb, Ni, Sn, Ta, Zr, and/or Hf, and x, y, z are numbers such that0.ltoreq.x.ltoreq.0.99,0.01.ltoreq.y.ltoreq.0.03, and8.5
摘要:
Disclosed is a rare earth-based, magnetically anisotropic permanent magnet material consisting of a rare earth element, e.g., neodymium or praseodymium, iron optional in combination with cobalt and boron and having excellent magnetic properties by virtue of the magnetic coupling between the magnetically hard and soft phases. The magnet material has a structure consisting of crystalline particles of, e.g., Nd.sub.2 Fe.sub.14 B, having a particle diameter of 1 .mu.m or larger and fine crystals of iron of submicron size in a rod-shaped or platelet form precipitated within each crystalline particle of Nd.sub.2 Fe.sub.14 B. This magnet material can be prepared by several different methods including, for example, a solid phase reaction of an intermetallic compound of Nd.sub.2 Fe.sub.17 with boron to effect a double decomposition reaction producing Nd.sub.2 Fe.sub.14 B and iron.
摘要翻译:公开了一种稀土类磁性各向异性永磁材料,其由稀土元素(例如钕或镨)组成,铁与钴和硼组合可选,并且由于磁性硬和 软相。 磁体材料具有由例如粒径为1μm以上的Nd 2 Fe 14 B的结晶粒子构成的结构,在Nd 2 Fe 14 B的各结晶粒子内析出棒状或者血小板形状的亚微米尺寸的铁的微细结晶。 该磁体材料可以通过几种不同的方法制备,包括例如Nd 2 Fe 17的金属间化合物与硼的固相反应,以产生产生Nd 2 Fe 14 B和铁的双重分解反应。
摘要:
The invention provides a method for producing a magnetic bias field in a magnetic bubble domain memory device. The method comprises coupling a magnetic bubble domain element with a permanent magnet. The permanent magnet is formed of a rare earth metal-containing alloy for use in the bubble domain memory device in respect of the reversible temperature coefficient of the magnet capable of being in compliance with the temperature coefficient of the bubble disappearance field of the memory device. The alloy characteristically contains nickel as an essential component so that the composition of the alloy is expressed by the formulaR(Co.sub.1-x-y Cu.sub.x Ni.sub.y).sub.z,in which R is a rare earth element, e.g. samarium or cerium, and s, y and z are each a positive number from 0.001 to 0.4, from 0.001 to 0.6 and from 4.0 to 9.0, respectively, with the proviso that x+y is smaller than 1.
摘要:
An improvement is proposed in the method for the preparation of a magnetic recording medium by forming a magnetic recording layer of a magnetic alloy on the surface of a non-magnetic substrate plate of, e.g., silicon so as to impart the magnetic recording medium with improved CSS (contact-start-stop) characteristics still without affecting the magnetic recording density. The improvement can be obtained by subjecting the surface of the substrate plate, prior to the formation of the magnetic recording layer, to a surface-roughening treatment which is performed either by a dry-process such as plasma etching and reactive ion etching or by a wet-process of anisotropic etching by using an aqueous solution of sodium or potassium hydroxide as the anisotropic etching solution. In particular, the plasma etching or reactive ion etching is conducted in the presence of a particulate scattering source body of aluminum, etc. placed in the vicinity of the CSS zone so that the surface-roughening effect is limited to the CSS zone by the deposition of particulates scattered therefrom leaving the recording zone unroughened not to decrease the recording density.