Abstract: The present invention relates to a process for forming a composite strip material without any sintering step. The process includes blending a powdered high conductivity material such as powdered copper with a powdered low thermal expansion phase material such as a nickel-iron alloy, compacting the powders to form a green composite strip, heating the green strip to a hot rolling temperature and hot rolling the heated strip to a desired gauge. The heated strip is reduced less than about 45% to minimize the deformation of the low thermal expansion phase particles.

Abstract: A process for the production of a powder having a nanocrystalline structure from powders of at least two materials of the groups including metals, metallic compounds, and ceramic materials, in a composition which tends to develop an amorphous phase. The starting powders are subjected to high stresses of at least 12 G in a neutral or reducing atmosphere at about 20.degree. C. until there are no crystallites larger than about 10 nm.

Abstract: Method and apparatus for forming an improved missile warhead comprising a cap section, a center section, and a mounting section, the three sections forming a tubular body closed by the cap section at one end thereof, with a plurality of cavities formed on the inner circumference of the center section. In formation of the cavity-bearing missile body, a missile body preform is isostatically formed from powder material along with low-density inclusions, the latter being removed during later processing to form an array of cavities, relying upon differential material densification for release of the inclusions from the pressed preform.

Abstract: A beryllium metal matrix phase includes up to 70% by volume of beryllium oxide single crystals dispersed therein. The composites are useful for electronics applications because of their light weight, high strength and effective thermal properties.

Abstract: This invention relates to a process for producing a rare earth-containing material capable of being formed into a permanent magnet comprising crushing a rare earth-containing alloy and treating the alloy with a passivating gas at a temperature below the phase transformation temperature of the alloy. This invention further relates to a process for producing a rare earth-containing powder comprising crushing a rare earth-containing alloy in a passivating gas at a temperature from ambient temperature to a temperature below the phase transformation temperature of the material. This invention also relates to a process for producing a rare earth-containing powder comprising crushing a rare earth-containing alloy in water, drying the crushed alloy material at a temperature below the phase transformation temperature of the material, and treating the crushed alloy material with a passivating gas at a temperature from the ambient temperature to a temperature below the phase transformation temperature of the material.

Abstract: The invention provides a method for removing the oxide surface from water atomized metal powders containing an oxidizer capable of oxidizing chromium from a trivalent to a soluble hexavalent state, whereby chromium oxides are removed from the metal powder surface. The powder is then treated with a dilute acid solution essentially devoid of hydrofluoric acid to remove other hydrated oxides from the metal powder surface. The powder is then water washed and dried.

Abstract: A method of making a disc-shaped or plate-shaped sintered body from powdered material of poor ductility, such as Sendust alloy, wherein the powdered material is filled in a dish-like metallic vessel having a thick bottom wall and a low side wall, a plurality of such filled vessels are piled up and put in a cylindrical capsule made of hot-workable metal, the capsule is charged in a container of a hot extrusion press whose outlet is closed and it is then heated and compressed. The resultant compressed product is taken out and cooled and metallic parts resulted from the vessels and capsule are removed from the compressed product, thereby obtaining plate-shaped sintered bodies as wanted.

Abstract: A method for making an anisotropic or predominantly unidirectional wick primarily for use in heat pipes is disclosed unidirectional heat pipe wicks is made by supporting magnetically susceptible particles on a wire screen and moving the screen inside a magnetic field until the characteristic cone or point shapes assumed by the particles are aligned in a laid down orientation. The particles are then heat treated to yield a sintered wick. An example of a wick made with nickel powder demonstrates improved wicking in the direction pointed to by the laid down points. A wick is also made by the spinning pipe-slurry method for making heat pipe wicks. Magnetically susceptible powder is mixed into a viscous binder to make a slurry, then injected inside a rotating cylindrical heat pipe container. A magnetic field is created around the spinning container and varied to align the particles in a desired structure.

Abstract: A method of manufacturing dispersion-strengthened material wherein a first material having a metal matrix M and at least one metal X capable of reacting with boron is supplied in a molten state to a mixing region at a first velocity. A second material having a metal matrix M and boron is supplied to the mixing region at a second velocity. The materials impinge on one another to produce a reaction between the metal X and the boron to form a boride in the metal matrix M. The mixture is solidified and pulverized to a powder which is then cleaned and consolidated.

Abstract: To permit an economical manufacture of high-strength sintered members for use in valve timing mechanisms of internal combustion engine by powder metallurgy with liquid-phase sintering, an iron-base powder mixture is provided, which contains 13 to 18% by weight chromium or 3 to 6% by weight molybdenum as a carbide-forming alloying element in the iron alloy powder and also contains 1.5 to 2.6% carbon and 0.4 to 1.0% by weight phosphorus. A corresponding molten iron alloy is atomized into an entraining gas or water jet and is subsequently mixed with the remaining components of the powder.

Abstract: A method for producing a camshaft having a tubular steel shaft and a sintered cam piece joined to the shaft. The sintered cam piece has iron tetroxide film at its surface. The camshaft is produced by assembling a powder compact to the steel shaft to provide a camshaft assembly, sintering the assembly to provide an integral assembly, correcting bending to the assembly, annealing the assembly, grinding the cam piece and effecting vaporization treatment to the assembly at a temperature lower than the annealing temperature.

Abstract: Shaped parts are formed from a powder having the desired chemistry of the finished part by mixing the powder with a thermosetting condensation resin that acts as a binder. The resin may be partially catalyzed, or additives or surfactants added to improve rheology, mixing properties, or processing time. Upon heating, the inherently low viscosity mixture will solidify without pressure being applied to it. A rigid form is produced which is capable of being ejected from a mold. Pre-sintered shapes or parts are made by injection molding, by using semi-permanent tooling, or by prototyping. Binder removal is accomplished by thermal means and without a separate debinding step, despite the known heat resistance of thermosetting resins. Removal is due to the film forming characteristic of the binder leaving open the part's pores, by providing oxidizing conditions within the part's pores as the part is heated, and by insuring that the evolving resin vapor diffuses through the pores by heating the part in a vacuum.

Abstract: Shaped parts are formed from a powder having the desired chemistry of the finished part by mixing the powder with a thermosetting condensation resin that acts as a binder. The resin may be partially catalyzed, or additives or surfactants added to improve rheology, mixing properties, or processing time. Upon heating, the inherently low viscosity mixture will solidify without pressure being applied to it. A rigid form is produced which is capable of being ejected from a mold. Pre-sintered shapes or parts are made by injection molding, by using semi-permanent tooling, or by prototyping. Binder removal is accomplished by thermal means and without a separate debinding step, despite the known heat resistance of thermosetting resins. Removal is due to the film forming characteristic of the binder leaving open the part's pores, by providing oxidizing conditions within the part's pores as the part is heated, and by insuring that the evolving resin vapor diffuses through the pores by heating the part in a vacuum.

Abstract: A composition containing 30 to 70% chromium carbide, 5 to 20% soft noble metal, 5 to 20% metal fluorides, and 20 to 60% metal binder is used in a powdered metallurgy process for the production of self-lubricating components, such as bearings. The use of the material allows the self-lubricating bearing to maintain its low friction properties over an extended range of operating temperatures.

Abstract: Coating with high-melting metals can be simplified by alloying high-melting metal with sufficient aluminum to make low-melting alloy that is applied, bonded in place, and then subjected to the leaching out of some or most of the aluminum. The resulting surface is porous and will receive and hold top coatings. Leached surface can be pyrophoric and top coating can be exothermically combustible. Pyrophoric powder can also be coated on boron or carbon fibers or sintered with combustible particles. Carbon can be kept from contaminating diffusion-treated workpieces, by conducting diffusion treatment in retorts containing little or no carbon. Porosity can be created by subjecting workpiece to diffusion conditions in contact with depleting material such as powdered nickel or high-nickel aluminides or cobalt or high-cobalt aluminides. Aluminum particles can be electrophoretically deposited on foil and then diffused in. Leaching aluminum out with caustic is improved when a little H.sub.2 O.sub.

Abstract: In a process for making tools from medium and high alloy steels or stellites by superplastic precision forming a powder metallurgically produced starting material with an equiaxed structure and more than 30% by volume of carbidic and/or boridic precipitated phase of particle size 1 to 0.2 .mu.m is given a matrix grain size of 1 to 3 .mu.m by thermomechanical processing (hot forming) and formed in the superplastic state.

Abstract: A Ca carbonate powder, a Sr carbonate powder, and a Cu oxide powder are mixed in predetermined proportions, and sintered at a first predetermined temperature into a Ca-Sr-Cu--O oxide sintered body. A Bi oxide powder and a Pb oxide powder are mixed in predetermined proportions, and are sintered at a second predetermined temperature into a Bi--Pb--O oxide sintered body. The obtained Ca--Sr--Cu--O oxide sintered body and Bi--Pb--O oxide sintered body are crushed, and the resulting Ca--Sr--Cu--O oxide powder and Bi--Pb--O oxide powder are mixed in predetermined proportions. The resulting mixed powder is sintered at a third predetermined temperature into a Bi--Pb--Sr--Ca--Cu--O superconductive oxide sintered body, which is crushed into a powder of a Bi-based superconductive oxide containing Pb. A sintered body of the Bi-based superconductive oxide containing Pb is formed from the Bi-based superconductive oxide powder.

Abstract: According to a method for making a compact consisting essentially of pure tungsten metal powder, the tungsten metal powder is contacted with an aqueous acid mixture at a sufficient concentration and for a sufficient period of time to etch the surface of the powder and the resulting powder is isostaticly pressed at an ambient temperature at a pressure of from about 18,000 to about 20,000 psi. for a sufficient period of time to form a compact.

Abstract: This invention relates generally to materials and processes for making materials and, more particularly, to high performance boride dispersion strengthened materials, including alloy-modified, boride dispersion strengthened materials and techniques for making such materials.

Abstract: Particles for the production of permanent magents are obtained by producing an article having Ca and a rare earth oxide including at least Nd oxide. The article is heated to effect Ca rare earth oxide reduction. Thereafter, particles of -60 mesh or finer are formed from this article. Leaching of Ca from the particles is achieved by contacting the particles with an organic acid having at least 3 carbon atoms, preferably propionic or butanoic acid.

Abstract: The invention relates to a method of producing a sintered Nd-Fe-B magnet which has a cylindrical or annular shape and is magnetized in radial directions with polar anisotropic orientation. In a cylindrical mold cavity filled with a Nd-Fe-B magnetic alloy powder a pulse of magnetic field is produced so as to cause polar anisotropic orientation of the magnetic powder with at least six poles distributed around the circumference, and a pulse-like pressure is applied to the powder in the mold cavity to compact the powder into a cylindrically shaped body while the pulse of magnetic field is lasting. The shaped body is sintered, and subsequently the side surface of the sintered body is abraded to remove projecting regions, which are attributed to anisotropic shrinkage during sintering, until the surface becomes accurately cylindrical.

Abstract: The cathode-forming method involves incorporating cobalt into a nickel plaque so that the exposed surfaces and the pores of the nickel plaque are uniformly covered with cobalt. The plaque is then treated to form nickel hydroxide in the pores and on the surfaces thereof. The cobalt is thus diposed at the interfacial boundary of the nickel plaque and nickel hydroxide so as to reduce the impedance and enhance charge conduction of the cathode. The mode of incorporation can vary. Thus, the sintered nickel plaque can be soaked in an aqueous solution of a water-soluble salt of cobalt, such as cobalt nitrate, then dried and resintered. Another mode involves dispersing a water-soluble cobalt salt in an aqueous slurry of nickel particles and water-soluble binder for the particles. The nickel particles are thus uniformly covered with the dissolved cobalt salt and then are compacted into a plaque. The plaque is dried and finally sintered.

Abstract: A method for pickling and consolidating water atomized metallic powders to reduce surface oxides. The technique includes introducing the powder into an acid bath--preferably nitric acid and hydrofluoric acid, rinsing the powder, introducing the powder into an alkaline bath, rinsing the powder and then consolidating the powder into a workpiece. Alternatively, the powder can be additionally introduced into a second acid bath and/or placed into a finishing boric acid bath before consolidation.

Abstract: The invention includes an isostatic press supply of heat to a workpiece by microwave energy and a method for isostatically pressing a powdered ceramic or powdered metal material that is heated by microwave energy. The isostatic press includes a pressure vessel. A fluid medium is available for supply to the pressure vessel under pressure. The invention further includes a means for transmitting microwave energy into the pressure vessel. The method includes preparing a workpiece comprising a microwave coupler material. Desirably, the workpiece is a composition comprising a powdered coupler or semiconductor and a powdered insulator. The workpiece is immersed in an additional powdered insulator which is transparent to the microwave energy. The workpiece and immersing powdered insulator are contained in a closed, compressible container. The contained, immersed workpiece is then placed into a pressure vessel.

Abstract: A protective coating system for superalloys is described. The coating is an active element enriched aluminide, and can be formed by aluminizing an overlay coated superalloy, wherein during the aluminizing process, aluminum diffuses completely through the overlay coating and into the substrate. The coating system exhibits desirable oxidation resistance and resistance to thermal fatigue cracking, due to the presence of oxygen active elements in the overlay.

Abstract: The present invention relates to the preparation of permanent magnet materials of the Iron-Boron-Rare Earth type.

Abstract: Apparatus and methods for compressing a mass utilizing a plurality of interfitting anvils mounted for movement relative to one another along co-planar paths and include faces which, when the anvils are operatively moved relative to one another, exert compression on a mass positioned between the faces in at least two directions in a plane simultaneously. The faces of the apparatus can be so shaped that the cross section of the mass being compressed is urged toward a shape other than that of a regular polygon. Methods of the invention include the consolidation of a mass of compactable material enclosed within a hollow tube having deformable walls, the extraction of juice or oil from fruit or seeds and the internal fracturing of solids so as to swell materials such as solid rocket propellants.

Abstract: A silver base electrical contact material is described which contains a dispersion of particles consisting of cadmium oxide and nickel. The nickel particles are surrounded by a continuous adherent coating of nickel oxide which eliminates the detrimental reaction which would otherwise occur between nickel and cadmium oxide. The invention contact materials have improved lives and are fabricated by any one of several different powder metallurgy techniques.

Abstract: Al-alloy containing Si, Fe, Cu and Mg and at least one kind of Mn and Co in the basic composition range of 8.0.ltoreq.Si.ltoreq.30.0 wt. %, 2.0.ltoreq.Fe.ltoreq.33.0 wt. %, 0.8.ltoreq.Cu.ltoreq.7.5 wt. %, 0.3.ltoreq.Mg.ltoreq.3.5 wt. %, 0.5.ltoreq.Mn.ltoreq.5.0 wt. % and 0.5.ltoreq.Co.ltoreq.3.0 wt. %, are provided in a powder state. A sindered member formed of these Al-alloys has a high strength and reveals excellent heat-resistivity and stress corrosion cracking resistivity. A structural member made of the sintered all-alloy is manufactured through the steps of subjecting a powder press-shaped body formed at a temperature of 350.degree. C. or lower and at a pressure of 1.5.about.5.0 ton/cm.sup.2 to hot extrusion working at a temperature of 300.degree..about.400.degree. C. to form a raw material for forging, and then forge shaping the raw material at a temperature of 300.degree..about.495.degree. C.

Abstract: The present invention relates to an infiltrated ferrous powder metal part containing certain additives, yielding a radically improved unnotched impact strength without sacrificing tensile strength. Fatigue strength is also improved. In addition, improved dimensional control is obtained during infiltration. The microstructure is also improved, with smoothing or rounding of the formerly sharp angled copper filled pores. The invention also comprises the method of achieving these results.

Abstract: An economical alloyed powder for dental amalgams exhibiting good working properties is obtained from pressed and sintered molded bodies by mechanical comminution. The formed body is produced by mixing and pressing powders of elemental silver, copper and tin with a subsequent sintering between 150.degree. C. and the solidus temperature of the alloy being formed. The sintering is performed until a homogeneous distribution of the tin has been achieved in the silver and copper particles.

Abstract: A composition of matter comprised of copper and particles which are dispersed throughout the copper, where the particles are comprised of copper oxide and copper having a coating of copper oxide, and a method for making this composition of matter.

Abstract: A method of manufacturing high-zirconium getters that involves hydrogen pulverization of an entire alloy ingot or ingot pieces. The method offers distinct advantages over techniques that use mechanical means of powder production. The method is useful expecially in the manufacture of tough porous getters, of high Zr-content Zr-V alloys that have minor additions of elements such as Fe, Ni, Mn and/or Al.

Abstract: The present invention relates to a process for the production of chromium-aluminum balls for adding chromium into molten aluminum baths.In order to obtain balls containing x% of chromium and y% of aluminum, where x and y are gravimetric contents corresponding to the following relationships:70.ltoreq.x.ltoreq.8020.ltoreq.y.ltoreq.30x+y=100an alloy of chromium and aluminum containing gravimetric chromium and aluminum contents approximating to x by an excess and to y by a deficit respectively is prepared by melting and this alloy is then finely ground into a crude powder; the chromium and aluminum contents of the alloy or of the crude powder are determined and, if required, an additional amount of finely divided aluminum is added so as to obtain a powder containing x% of chromium and y% of aluminum, the additional amount of finely divided aluminum corresponding to less than 10% by weight of the crude powder; a compacting is then carried out.

Abstract: An improved method for the continuous fabrication of metal-hydride, electrochemical, hydrogen storage alloy, negative electrodes for use in rechargeable nickel metal hydride cells. The improved method comprises the steps of providing measured amounts of powdered metal hydride electrochemical hydrogen storage alloy material and disposing said material upon a continuous wire mesh screen substrate. Thereafter, the powdered metal hydride electrochemical hydrogen storage alloy and wire mesh screen are subjected to a compaction process wherein they are rolled and pressed so as to form a single integral electrode web which is subsequently exposed to a high temperature sintering process in a chemically inert environment. The sintering process is designed to drive off excess moisture in the material while discouraging oxidation of the electrode web and set the electrode web state of charge.

Abstract: A method for pickling and consolidating water atomized metallic powders to reduce surface oxides. The technique includes introducing the powder into an acid bath--preferably nitric acid and hydrofluoric acid, rinsing the powder, introducing the powder into an alkaline bath, rinsing the powder and then consolidating the powder into a workpiece. Alternatively, the powder can be additionally introduced into a second acid bath and/or placed into a finishing boric acid bath before consolidation.

Abstract: A metal matrix composite is produced by plastically deforming a metal powder, either or after blending the powder with ceramic fibers, and compacting the mixture at elevated temperatures to achieve substantially full density. Imparting strain energy to the metal allows reduction of the compaction temperature to eliminate reaction between the fibers and the metal or degradation of the fibers. Silicon nitride fibers are thermodynamically superior for use in aluminum or titanium metal matrix composites, since silicon nitride fibers are more stable at the temperatures required for full compaction. Secondary phase reactions are avoided.

Abstract: A method and apparatus for producing spherical objects is disclosed, the apparatus having a reservoir filled with a relatively dense molten material, the reservoir being heated and hydraulically pressurized to maintain the molten state of the dense material. A second molten liquid, of lesser density and higher melting point is injected into the reservoir, the pressure and surface tension acting to force the injected material into a spherical form and the melting point difference acting to solidify the injected material.

Abstract: The invention relates to a method and means for removing liquid from moist metal particles, substantially without causing oxidation, preferably from metal particles produced by means of liquid atomization of a casting jet, wherein the moist metal particles are collected in a space (1) and a non-oxidizing gas flow is blown through them, most of the moisture being caused to accompany the gas flow out of the space (1) and wherein the space, in which the metal particles are filled, is thereafter substantially evacuated so that any remaining liquid is vaporized and thus removed from the space (1).

Abstract: A sintered magnet of Fe-B-rare earth alloy having an axis of easy magnetization oriented at an angle to a major axis can be directly produced from the alloy material by (a) press molding the material in an applied magnetic field into a compact of the dimensions determined by taking into account factors of shrinkage expected in X, Y and Z directions, and (b) sintering the compact.

Abstract: A microcomposite material having a matrix of a titanium-base alloy, the material further including about 10-80% by weight TiC substantially uniformly dispersed in the matrix. Several methods of cladding a macrocomposite structure including pressing quantities of a matrix material and a microcomposite material composed of the matrix material and a compatible stiffener material into layers to form a multi-layered compact and sintering the multi-layered compact to form an integral metallurgical bond between the layers of the compact with diffusion but essentially no composition gradient between the layers. A multi-layered macrocomposite article composed of an alloy layer of a matrix material and a layer of a microcomposite material composed of the matrix material and a compatible stiffener material bonded together at the interface region between the layers, the interface region being essentially free of a composition gradient.

Abstract: (1) A process comprising spray drying a powder-containing slurry, the slurry containing a powder constituent susceptible of oxidizing under the temperature conditions of the spray drying, while reducing the tendency for oxidation of the constituent by including as a liquid constituent of the slurry an organic liquid; (2) a process comprising spray drying a powder-containing slurry, the powder having been pretreated to reduce content of a powder constituent susceptible of oxidizing under the temperature conditions of the spray drying, the pretreating comprising heating the powder to react the constituent; and (3) a process comprising reacting ceramic powder, grinding the reacted powder, slurrying the ground powder, spray drying the slurried powder, and blending the dried powder with metal powder.

Abstract: The disclosure relates to a method whereby complex shapes, not moldable in a single molding operation, are molded in plural parts, each part being of the same or different powdered metal composition or prealloy of the type disclosed. One or more of the parts preferably has bumps or dimples thereon for joining to another of the parts in the manner to be described. The other part can also have depressions for receiving the bumps to aid in alignment of the parts prior to processing.

Abstract: A chemical pretreatment method is used to produce boron carbide-, boron-, and boride-reactive metal composites by an infiltration process. The boron carbide or other starting constituents, in powder form, are immersed in various alcohols, or other chemical agents, to change the surface chemistry of the starting constituents. The chemically treated starting constituents are consolidated into a porous ceramic precursor which is then infiltrated by molten aluminum or other metal by heating to wetting conditions. Chemical treatment of the starting constituents allows infiltration to full density. The infiltrated precursor is further heat treated to produce a tailorable microstructure. The process at low cost produces composites with improved characteristics, including increased toughness, strength.

Abstract: A process for producing titanium alloy articles by Hot Isostatic Pressing of a rapidly-solidified titanium alloy powder is provided wherein such pressing is carried out at a pressure greater than 30 ksi, and a temperature of about 60 to 80 percent of the beta-transus temperature of the alloy, in degrees C. Hot Isostatic Pressing under these conditions allows retention of the fine microstructure of the rapidly-solidified powder. The compacted article may be subjected to heat treatment to alter its microstructure.

Abstract: A manufacturing method of super-heat-resisting alloy material characterized in comprising the steps of: (1) filling and sealing the powder of Ni-based super-heat-resisting alloy in a rubber mold; (2) subjecting the powder in the rubber mold to cold isostatic pressing; (3) sintering the compact in vacuum or in gas atmosphere at a temperature of 1000.degree. C. or more so that the sintered density increases to 95% or more than the theoretical density; and (4) next, subjecting the sintered compact to hot isostatic pressing.

Abstract: A method of producing a sintering powder made from high speed steel and alumina. This sintering powder is sinterable over a broader range of temperatures than conventional high speed steel sintering powders and at lower temperatures, thereby making sintered objects which are crack resistant and also highly wear resistant. Additionally, the sintering powder flows readily when poured into a mold for production of a green object for sintering.

Abstract: A method is disclosed for manufacturing a reaction sintered composite article which comprises at least one ceramic component. The method comprises preparing a particulate mixture of precursor powders leading to the formation of said composite material upon reaction sintering, pressing said particulate mixture to a self-sustaining body, heating said body up to a temperature below the temperature at which the reaction sintering is initiated, comminuting the heat treating body, selecting particles of a suitable grain size distribution, pressing said particles into shapes of desired size and configuration, and heating said shapes up to a temperature at which the reaction sintering is initiated. The reaction sintered body comprises borides, carbides, nitrides or silicides of a transition metal of the groups IVb, Vb or VIb of the periodic table (comprising titanium, hafnium, zirconium, vanadium, niobium, tantalum, chromium, molybdenum and tungsten), and a metal oxide.

Abstract: An electrical contact for vacuum interrupters of a pressed and sintered composition of copper (60-80 wt %), ferrovanadium alloy (40-100 wt % of the balance) with at least 80 wt % of any remainder consisting of a refractory metal of the group of chromium, vanadium and their compounds. The ferrovanadium alloy comprises 55-85 wt % of vanadium.

Abstract: 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.