Classifications

• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01F—MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
  • H01F1/00—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties
  • H01F1/01—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties of inorganic materials
  • H01F1/03—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties of inorganic materials characterised by their coercivity
  • H01F1/032—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties of inorganic materials characterised by their coercivity of hard-magnetic materials
  • H01F1/04—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties of inorganic materials characterised by their coercivity of hard-magnetic materials metals or alloys
  • H01F1/06—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties of inorganic materials characterised by their coercivity of hard-magnetic materials metals or alloys in the form of particles, e.g. powder
  • H01F1/08—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties of inorganic materials characterised by their coercivity of hard-magnetic materials metals or alloys in the form of particles, e.g. powder pressed, sintered, or bound together
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B22—CASTING; POWDER METALLURGY
  • B22F—WORKING METALLIC POWDER; MANUFACTURE OF ARTICLES FROM METALLIC POWDER; MAKING METALLIC POWDER; APPARATUS OR DEVICES SPECIALLY ADAPTED FOR METALLIC POWDER
  • B22F3/00—Manufacture of workpieces or articles from metallic powder characterised by the manner of compacting or sintering; Apparatus specially adapted therefor ; Presses and furnaces
  • B22F3/006—Amorphous articles
  • B22F3/007—Amorphous articles by diffusion starting from non-amorphous articles prepared by powder metallurgy
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B22—CASTING; POWDER METALLURGY
  • B22F—WORKING METALLIC POWDER; MANUFACTURE OF ARTICLES FROM METALLIC POWDER; MAKING METALLIC POWDER; APPARATUS OR DEVICES SPECIALLY ADAPTED FOR METALLIC POWDER
  • B22F3/00—Manufacture of workpieces or articles from metallic powder characterised by the manner of compacting or sintering; Apparatus specially adapted therefor ; Presses and furnaces
  • B22F3/12—Both compacting and sintering
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B22—CASTING; POWDER METALLURGY
  • B22F—WORKING METALLIC POWDER; MANUFACTURE OF ARTICLES FROM METALLIC POWDER; MAKING METALLIC POWDER; APPARATUS OR DEVICES SPECIALLY ADAPTED FOR METALLIC POWDER
  • B22F9/00—Making metallic powder or suspensions thereof
  • B22F9/02—Making metallic powder or suspensions thereof using physical processes
  • B22F9/04—Making metallic powder or suspensions thereof using physical processes starting from solid material, e.g. by crushing, grinding or milling
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B22—CASTING; POWDER METALLURGY
  • B22F—WORKING METALLIC POWDER; MANUFACTURE OF ARTICLES FROM METALLIC POWDER; MAKING METALLIC POWDER; APPARATUS OR DEVICES SPECIALLY ADAPTED FOR METALLIC POWDER
  • B22F9/00—Making metallic powder or suspensions thereof
  • B22F9/02—Making metallic powder or suspensions thereof using physical processes
  • B22F9/04—Making metallic powder or suspensions thereof using physical processes starting from solid material, e.g. by crushing, grinding or milling
  • B22F2009/041—Making metallic powder or suspensions thereof using physical processes starting from solid material, e.g. by crushing, grinding or milling by mechanical alloying, e.g. blending, milling

Definitions

• the invention relates to a method for producing a metallic body from an amorphous alloy, in particular from a metallic glass, in which - An intermediate product is formed from at least two powdery, at least partially magnetic components of the alloy by performing a compacting step in such a way that the alloy components in the intermediate product are each expanded in at least one dimension by at most 1 ⁇ m, and - The intermediate product is converted into the metallic body by means of a diffusion reaction at a predetermined elevated temperature.
• Amorphous materials referred to as "metallic glasses” are generally known (cf., for example, "Zeitschrift für Metallischen”, volume 69, 1978, number 4, pages 212 to 220 or “Elektrotechnik und Maschinenbau", 97th year, September 1980, number 9, Pages 378 to 385).
• These materials are generally special alloys which are to be produced from at least two predetermined starting elements or compounds, also referred to as alloy components, by means of special processes. Often the material of at least one of the elements or one of the connections is magnetic.
• These special alloys have a glass-like, amorphous structure instead of a crystalline one and have a number of unusual properties or combinations of properties such as high wear and corrosion resistance, great hardness and tensile strength with good ductility as well as special magnetic properties.
• microcrystalline materials with interesting properties can be produced (see, for example, DE-PS 28 34 425).
• metallic glasses have generally been produced by rapid quenching from the melt (cf. also DE-OS 31 35 374 or 31 28 063). However, this method results in at least one dimension of the material produced being less than about 0.1 mm. For various uses, however, it would be desirable if metallic glasses of any shape and size were available.
• a certain microstructure is also required, in that the alloy components involved are closely adjacent and each have very small dimensions below 1 ⁇ m in at least one dimension.
• layer structures are particularly suitable, which can be produced, for example, by vapor deposition (cf., for example, the cited reference from “Phys.Rev.Letters", vol. 51).
• layering of thin metal foils is also possible for this (cf., for example, "Proc. MRS Europe Meeting on Amorphous Metals and Non-Equilibrium Processing", ed. M. von Allmen, France, 1984, pages 135 to 140).
• a corresponding layer-like structure can also be obtained by the process which can be found in the publication "View through the Economy” mentioned at the beginning.
• metal alloys of the desired composition are first mixed as alloy components and then compacted into an intermediate product.
• This intermediate product in which the alloy components are each expanded in at least one dimension by at most 1 ⁇ m, is subsequently converted into the desired metallic body with an amorphous structure by anomalous rapid diffusion at a predetermined elevated temperature.
• a method which has been proposed with the unpublished DE patent application P 35 15 167.6 can be used for the large-scale production of metallic bodies with a relatively extensive shape and dimension from amorphous alloys, in particular using hard-to-deform or brittle alloy components.
• a mixed powder is first produced by means of a grinding process known per se from the mostly crystalline powders of the starting elements or compounds representing the alloy components, the individual particles of which are built up approximately in layers from the starting elements or compounds.
• the point in time at the end of the grinding process at which this structure of the mixed powder particles is present can be determined, for example, by experimental investigation of the particles, easily determine and thus determine.
• This mixed powder produced in this way is then compacted and / or deformed in a further working step to form a compact intermediate product with the desired shape and size adapted to the body.
• This compact intermediate product still consists of crystalline parts of the starting elements or compounds, the dimensions of which in at least one dimension are less than 1 ⁇ m or even less than 0.2 ⁇ m.
• the intermediate product is then converted in a manner known per se into the desired metallic body made from the amorphous alloy or from the metallic glass.
• the powder is compacted either by extrusion or by other shaping methods such as hammering.
• This deformation causes a reduction in the individual layer thicknesses if the layers are parallel to the direction of deformation.
• powder particles with layers arranged largely in parallel are obtained by the grinding process, the particles are not aligned during compacting, so that the arrangement of the individual layers is statistically distributed with respect to the direction of deformation.
• layers that are perpendicular to the direction of deformation an increase in the layer thickness can even result during the deformation, whereas layers that are predominantly parallel to the direction of deformation become thinner during the deformation.
• the statistically oriented alignment of the layers before the compacting may therefore lead to an increase in the bandwidth of the layer thicknesses after the deformation; that is, the deformation during the compacting is not used.
• the object of the present invention is to design the method mentioned at the outset in such a way that, using at least one magnetic component, metallic bodies with a relatively extensive shape and dimension can be produced on an industrial scale from an amorphous or non-amorphous, crystalline alloy, in particular also difficult to deform and brittle alloy components are to be used and in the compacting step the individual layers are arranged parallel to a predetermined preferred direction, the later direction of deformation.
• the advantages associated with this embodiment of the method can be seen in particular in the fact that the particles of the mixed powder align themselves in an applied magnetic field of sufficient strength so that their layer-like structures lie approximately parallel to the magnetic field.
• the magnetic field is applied during the manufacturing process at least at a point in time at which the individual particles are still mobile, ie generally at least before the actual compacting step. Due to the special orientation of the individual layer-like structures of the mixed powder in the magnetic field, the result is that they become even thinner during the deformation, ie the deformation process for compacting is also used to further reduce the layer thicknesses. It is known that diffusion reactions between the particles are favored by correspondingly small layer thicknesses. This is particularly advantageous if an amorphous material is to be produced with the alloy components.
• the invention is further explained below on the basis of the production of a body from a special metallic glass.
• the at least two powdered alloy components do not necessarily all have to be metallic, but some of them can also be metalloids. However, at least one of these components must have magnetic properties. Generally the components will be crystalline; in special cases of the use of metalloids, however, amorphous powders such as e.g. can be provided from boron.
• One of the alloy components A or B should consist of a magnetic material.
• A can be, for example, magnetic Co and B can be non-magnetic Zr.
• corresponding other components for the formation of known two- or multi-component amorphous or non-amorphous alloys can also be used as well.
• powders of the two components A and B are first placed in a suitable grinding bowl together with hardened steel balls.
• the size of the powder can be of any size, but a similar size distribution of both components involved is advantageous.
• the body to be manufactured in powder is determined by the ratio of the two types of powder.
• pure Co and Zr powders each with powder particle sizes of, for example, an average of approximately 40 ⁇ m each, can be introduced into a planetary ball mill (Fritsch brand: type "Pulverisette-5"), the steel balls of which each have a diameter of 10 mm. Varying the ball diameter and the number of balls causes any change in the grinding intensity.
• the steel container of the mill is sealed under protective gas, for example under argon, and only opened again after the grinding process has ended. During the grinding process, the powders are then flattened, welded and divided again. A predetermined temperature level below the crystallization temperature of the amorphous material to be formed can advantageously be maintained.
• the grinding process is achieved when the desired layer-like structure is reached, in which the layer-like regions generally have about 0.01 to 0.9 microns, preferably between 0.05 and 0.5 microns thick, canceled.
• the size of the powder particles themselves is approximately 10 to 200 ⁇ m in diameter.
• the predetermined point in time at which this desired structure of the powder particles is present can be determined, for example, by cutting the particles.
• the powder particles are still mobile, they are exposed to a constant magnetic field according to the invention. They then align themselves in such a way that their layer-like structures lie parallel to the magnetic field.
• the direction of the magnetic field is set so that it coincides with a later compaction direction.
• the way in which the powder particles are magnetically aligned depends on the respective compaction method. If, for example, a so-called isostatic pressing is used, either in connection with a simultaneous diffusion annealing as hot isostatic pressing or to form a shaped body for further deformation by extrusion, hammering or the like, the mixed powder is first filled into a deformable form. Then, with shaking and tapping, the magnetic field is then applied parallel to the longitudinal axis of the mold. The field strength for this can be in the range between 0.1 and 1 T. After the powder particles are aligned with their individual layers parallel to the field direction, the magnetic field can be switched off, the mold closed and the isostatic pressing process started. Care should be taken to ensure that the compact is handled carefully so that the powder does not rearrange itself.
• Another possibility is to first compress the powder in a uniaxial press to form a compact intermediate product or several tablet-like shaped pieces. After the preliminary product or the shaped pieces have been or have been sheathed, a further deformation step, such as Extrusion or hammering.
• the magnetic field must be applied after filling the mixed powder into the press die before pressing.
• the mixed powder can also be poured directly into a jacket, magnetically aligned and then extruded, hammered or otherwise deformed in the jacket to form a good compaction.
• the inventive alignment of the powder particles produced is carried out in a magnetic field at a temperature T which lies between the two Curie temperatures, ie that: T c A ⁇ T ⁇ T c B if T c A ⁇ T c B is (otherwise vice versa).
• the annealing temperature must in any case be below the crystallization temperature of the metallic glass in a known manner.
• the metallic body present as the end product at the end of this process thus consists of an amorphous alloy with a thickness and shape which is predetermined by the compacting process and can therefore be chosen as desired.

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• 1986
  • 1986-07-31 DE DE8686110624T patent/DE3669450D1/de not_active Expired - Fee Related
  • 1986-07-31 EP EP86110624A patent/EP0213410B1/fr not_active Expired - Lifetime
  • 1986-08-08 US US06/894,929 patent/US4743311A/en not_active Expired - Fee Related
  • 1986-08-11 JP JP61187039A patent/JPS6240329A/ja active Pending

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