US3559271A - Hydrostatic extrusion of powder - Google Patents

Hydrostatic extrusion of powder Download PDF

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Publication number
US3559271A
US3559271A US739487A US3559271DA US3559271A US 3559271 A US3559271 A US 3559271A US 739487 A US739487 A US 739487A US 3559271D A US3559271D A US 3559271DA US 3559271 A US3559271 A US 3559271A
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US
United States
Prior art keywords
powder
billet
pressure
extrusion
nozzle
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Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
Application number
US739487A
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English (en)
Inventor
Jan Nilsson
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ABB Norden Holding AB
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ASEA AB
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Publication date
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Publication of US3559271A publication Critical patent/US3559271A/en
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Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
    • B21C—MANUFACTURE OF METAL SHEETS, WIRE, RODS, TUBES OR PROFILES, OTHERWISE THAN BY ROLLING; AUXILIARY OPERATIONS USED IN CONNECTION WITH METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL
    • B21C23/00—Extruding metal; Impact extrusion
    • B21C23/007—Hydrostatic extrusion
    • 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
    • B22F3/20—Manufacture of workpieces or articles from metallic powder characterised by the manner of compacting or sintering; Apparatus specially adapted therefor ; Presses and furnaces by extruding
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C32/00—Non-ferrous alloys containing at least 5% by weight but less than 50% by weight of oxides, carbides, borides, nitrides, silicides or other metal compounds, e.g. oxynitrides, sulfides, whether added as such or formed in situ
    • C22C32/001—Non-ferrous alloys containing at least 5% by weight but less than 50% by weight of oxides, carbides, borides, nitrides, silicides or other metal compounds, e.g. oxynitrides, sulfides, whether added as such or formed in situ with only oxides
    • C22C32/0015—Non-ferrous alloys containing at least 5% by weight but less than 50% by weight of oxides, carbides, borides, nitrides, silicides or other metal compounds, e.g. oxynitrides, sulfides, whether added as such or formed in situ with only oxides with only single oxides as main non-metallic constituents
    • 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
    • B22F3/20—Manufacture of workpieces or articles from metallic powder characterised by the manner of compacting or sintering; Apparatus specially adapted therefor ; Presses and furnaces by extruding
    • B22F2003/202—Manufacture of workpieces or articles from metallic powder characterised by the manner of compacting or sintering; Apparatus specially adapted therefor ; Presses and furnaces by extruding with back pressure
    • 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
    • B22F3/20—Manufacture of workpieces or articles from metallic powder characterised by the manner of compacting or sintering; Apparatus specially adapted therefor ; Presses and furnaces by extruding
    • B22F2003/206—Hydrostatic or hydraulic extrusion

Definitions

  • the present invention relates to a method of producing rods or wire by means of hydrostatic extrusion, using powder as starting material.
  • Rods have also been produced by extruding powder with the addition of a binder through the die.
  • a binder has been necessary for the compression to take place under reasonable pressure and so that the powder is held together during further treatment.
  • the density of the powder is deteriorated due to this addition.
  • the binder is removed before sintering or disappears partly or completely during the sintering and thus gives rise to spaces between the powder particles or to shrinkage of the body resulting in poor mechanical properties and diiiculty in maintaining small tolerance.
  • Hot extrusion of powder is also known.
  • the high ternperature often above 1,000 C., causes considerable strain on the tools, however.
  • rods or wire are manufactured by means of hydrostatic extrusion of a billet consisting of powder of a single material or a mixture of powders of different materials to provide the desired cornposition. No binder is added. Usually metal powder is used, but certain oxide powder mixtures of metal and oxide powder or metal powder with oxide coating may also be used.
  • Normal commercial powder of copper, aluminium, iron, or the like having a particle size under 150g (under mesh) can be used.
  • the powder is shaped into a billet and compacted to great density and provided on its surface with a temporary, liquid-tight barrier of non-metallic, tenacious material, after which the billet is shaped into a bar or tube by means of hydrostatic extrusion in equipment comprising a pressure chamber, a die inserted in this chamber with a nozzle to give the billet the desired cross-section, a pressure medium enclosed in the pressure chamber and a pressure-generator to generate the pressure necessary in the pressure chamber for the extrusion. After the extiusion the temporary barrier is removed which, during the extrusion process, prevents the pressure medium from penetrating into the pores of the billet.
  • the temporary barrier suitably consists of a plastic material having a hardness of at least 60 Shore A. With this or greater hardness the plastic has such resistance that it is not pressed into the pores between the powder particles of the billet.
  • Plasticized PVC polyvinyl chloride
  • the plastic layer forming the barrier can be applied by bringing the heated billet into contact with a powder or grains of the plastic and afterwards possibly inserting it in a furnace and treating it there so that the plastic layer obtains the desired density and hardness. It is also possible to apply the plastic by dipping the billet in a melt or solution of the plastic or by spraying molten plastic or plastic dissolved in a solvent onto the billet. Before extrusion the billet should be compacted, for example by means of hydrostatic compacting, to a density which is at least 60% of the theoretically possible density, that is the density of a solid billet of the same material.
  • Compression with a counter-pressure may be necessary when extruding brittle materials or when, for some other reason, it is desirable or necessary to operate with low extrusion ratio.
  • the counter-pressure demands correspondingly higher pressure in the pressure chamber and greatly complicates the equipment. Higher counter-pressure than 4,0005,000 bar is hardly possible.
  • R 3 With counter-pressures of this magnitude R 3 is desirable if a crack-free product is to be obtained.
  • R 6 it is usually possible to obtain a crackfree product without using counter-pressure during the extrusion.
  • R 60 is required for sintering. If the extrusion takes place under counter-pressure the nozzle on the output side is connected to a pressure chamber in which a constant counter-pressure can be maintained with the help of control means for the purpose.
  • the method enables products to be manufactured from powder which have greater density than is possible with previously known methods.
  • the density involves more intimate contact between the powder particles, which enables the body to be more easily sintered.
  • the good particle contact involves less alteration in dimension during sintering and produces a nal product with better mechanical properties.
  • the powder used may consist of several substances, each of which is plastically formable. Upon extrusion a rod is formed in which the constituents, during the subsequent sintering, form those alloys which give the material the desired properties. In many cases it is possible to utilize the constituent alloying substances better and thus produce the desired properties in the finished product while using less of the alloying substances which usually constitute the most expensive particle components in the powder mixture.
  • rods can be produced having desired dimensions and small tolerance from material which in the form of a nished alloy cannot be plastically machined and therefore cannot be given the desired dimension yby rolling or forging.
  • a powder mixture having the same composition can be shaped by extrusion to rods, assuming that at least a certain proportion of the constituents are individually ductile. Examples of the above-mentioned alloys are:
  • Dispersion-tempered products with extremely good properties can also be manufactured with advantage according to the method.
  • Particles of hard material for example certain oxides
  • the separate particles are greatly deformed and the hard substances broken down to very small particles which are also very evenly distributed in the iinished rod.
  • the content of dispersion-tempered substances can be kept low since it is the free path between particles of the additional material which determines the properties of the product. With a low content of additional material its negative effect will be negligible. It is thus possible according to the method to manufacture aluminium conductors having great mechanical strength but approximately the same Conducting capacity as conductors of pure aluminium.
  • the shape of the extrusion nozzle is important for the quality of the surface of the extruded rod.
  • the nozzle should have a conical entrance part the acute angle of which should be greater than 25 and less than 90 depending on the material of the billet to be extruded. For most materials an acute angle of around 45 is suitable.
  • the Calibrating part of the nozzle below ythe entrance cone should have a certain minimum length if the best result is to be obtained. A length of approximately l mm. has been found suitable and sufficient for materials extruded so far.
  • FIG. 1 designates a high pressure chamber, extrusion chamber, formed by a steel cylinder 2 which is strongly pre-stressed with the help of a surrounding tape or a wire sheath 3, an extrusion nozzle 4 and a piston 5.
  • the piston 5 is connected to a piston l6 in a cylinder 7 with a lid ⁇ 8 through which the piston 5 passes.
  • the lid 8 is attached to the cylinder 7 by bolts 9.
  • 10 is a yoke which supports the cylinder 7 and absorbs pressure from it during the extrusion.
  • the cylinder rests on a table 11 which is joined to the yoke by means of columns, not shown in the drawing.
  • the nozzle 4 is arranged in a holder 12 sunk into the table 11.
  • a counter-pressure chamber 13 consisting of a tube'14 which is connected to the holder 12 and attached to the table 11 by means of flanges 15 and 'bolts 16.
  • the tube is closed by a lid 17 which is easily removed, for example by a bayonet catch, so that the extruded rods can be removed from the counter-pressure chamber 13.
  • the pressure chamber 13 is connected for pressure control by means of the channel 18 to a cylinder 19 with a piston 20 which is in turn connected to a piston 21 in a cylinder 22.
  • the lid 23 is attached to the cylinder 22 by means of bolts 24.
  • the lid 23 In the lid 23 are channels 25 and a valve seat 26 against which a valve body 27 is pressed by the spring -28, the tension of which can be regulated by the screw 29 so that the desired counter-pressure can be obtained in the chamber 13.
  • the cylinder 22 Through the channel 30 and conduits, not shown, the cylinder 22 is connected to a pressure source so that between pressure operations the plstons 20 and 21 can be moved to approximately the position shown in the drawing.
  • 31 is a billet to be extruded and 32 a rod which has left the pressure nozzle 4 and reached the counter-pressure chamber 13.
  • the cylinder 7 is connected by the channels 33 and 34 to a pressure source for operating the piston 6,
  • the space is, by means of the channel 41 and the -pipe fittings, not shown in the drawing, in connection with a collecting container for hydraulic Huid, 35, 36, 37, 38 and 39 are seals between construction elements in the hydraulic system.
  • a billet 31 consisting of a powder of one or usually several materials, normally metals, is shaped and surrounded by a yielding, liquid-tight casing. It is then compacted in a pressure chamber by means of a hydrostatic pressure. After compacting, the casing is removed and one end of the billet is shaped to fit the nozzle or die 4. The billet is provided with a new, thin, liquid-tight casing, for example a layer of varnish. The billet is then inserted in the pressure chamber 1 and the punch 5 is pushed by the piston 6 into the cylinder 2 so that pressure is generated in the chamber 1 which, when it reaches a certain value, is able to deform the billet so that it is pressed or extruded through the nozzle 4 and a rod 32 is obtained. This has extremely high density and great accuracy of dimension. In this way very small and uniform shrinkage is obtained during the subsequent sintering and the need for final processing is minimal.
  • the extrusion takes place under counter-pressure.
  • the rod 32 which leaves the nozzle 4 is pressed or extruded into a chamber 13 in which a constant counter-pressure is maintained during the extrusion process.
  • This pressure is maintained by a pressure-regulating means connected to the chamber 13 having a differential piston with the pistons 20 and 21 and a control valve with a valve body 27 actuated by the spring 2S, which permits liquid to pass out of the cylinder 22 when the pressure has reached a certain predetermined value.
  • the lid 17 is removed and the extruded billet taken out.
  • the piston is returned to its upper position by supplying liquid to the space below the cylinder 6 in the cylinder 7 through the channel 33.
  • the pistons 20 ⁇ and 21 are returned to the position shown in the drawing by supplying liquid to the cylinder 22 through the channel 30. A new working cycle can then be commenced.
  • Method of producing rods or wire of desired configuration from powder by hydrostatic extrusion comprising the steps of:
  • the temporary barrier consists essentially of a plastic layer with a hardness of at least 60r Shore A.
  • the ternporary barrier consists essentially of plasticized PVC (polyvinyl chloride).
  • the temporary barrier consists essentially of a plastic layer which is applied by bringing a heated billet into contact with powder or grains of plastic.
  • the temporary barrier consists essentially of a plastic layer which is applied by dipping in a melt or in a plastic dissolved in a solvent.
  • the ternporary barrier consists essentially of a layer of plastic material which is applied by spraying on a plastic or elastomeric material dissolved in a solvent.
  • Method according to claim 1 in which a powder consisting essentially of a mixture of substances which are individually plastically deformable, is formed by hydrostatic extrusion into a rod in which the constituents form alloys during subsequent sintering which give the rod material the desired properties.
  • Method according to claim 1 in which a powder of dispersion-tempering products is mixed into the metal powder.
  • Method according to claim l in which a billet extruded through the nozzle is subjected to a counter-pressure in a chamber connected to the nozzle externally.

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  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Chemical & Material Sciences (AREA)
  • Manufacturing & Machinery (AREA)
  • Materials Engineering (AREA)
  • Metallurgy (AREA)
  • Organic Chemistry (AREA)
  • Powder Metallurgy (AREA)
  • Extrusion Moulding Of Plastics Or The Like (AREA)
  • Extrusion Of Metal (AREA)
US739487A 1967-06-26 1968-06-24 Hydrostatic extrusion of powder Expired - Lifetime US3559271A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
SE6709071A SE377434B (de) 1967-06-26 1967-06-26

Publications (1)

Publication Number Publication Date
US3559271A true US3559271A (en) 1971-02-02

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US739487A Expired - Lifetime US3559271A (en) 1967-06-26 1968-06-24 Hydrostatic extrusion of powder

Country Status (6)

Country Link
US (1) US3559271A (de)
JP (1) JPS5132564B1 (de)
DE (1) DE1758540B1 (de)
FR (1) FR1569530A (de)
GB (1) GB1221879A (de)
SE (1) SE377434B (de)

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3771221A (en) * 1971-12-03 1973-11-13 Bbc Brown Boveri & Cie Method and apparatus for producing fine-particle permanent magnets
US4480453A (en) * 1983-12-09 1984-11-06 N P S P Po Hydroplastichna Obrabotka Na Metalite Apparatus for blast hydroplastic finishing of tubular billets
WO1985001246A1 (en) * 1983-09-12 1985-03-28 Battelle Development Corporation Methods of compaction by incremental radial compression and/or low-ratio extrusion
US5409662A (en) * 1992-02-08 1995-04-25 Hitachi Powdered Metals Co., Ltd. Method and apparatus for extruding powder material
CN106378361A (zh) * 2016-09-06 2017-02-08 南京理工大学 一种微型平面弹簧静液挤压的装置

Families Citing this family (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB1365717A (en) * 1970-12-21 1974-09-04 Bbc Brown Boveri & Cie Process for making permanent magnets from magnetic powders
DE2419014C3 (de) * 1974-04-19 1985-08-01 Nyby Bruks AB, Nybybruk Verfahren zum Herstellen von Rohren aus rostfreiem Stahl und Anwendung des Verfahrens auf das Herstellen von Verbundrohren
DE2462747C2 (de) * 1974-04-19 1984-02-23 Nyby Bruk AB, Nybybruk Strangpreßbolzen zur pulvermetallurgischen Herstellung von Rohren aus rostfreieem Stahl
US4005596A (en) * 1975-04-07 1977-02-01 Ural Viktor Ivanovich Apparatus for hydraulic pressing of metals
FR2453840A1 (fr) * 1979-04-11 1980-11-07 Fraga Dominguez Ramon Procede de fabrication de pierres a briquet et pierres ainsi obtenues
FR2684028B1 (fr) * 1991-11-27 1994-02-25 Centre Nal Recherc Scientifique Procede de fabrication d'une barre comprenant une ame poudreuse gainee d'une matiere metallique.
DE10135485A1 (de) * 2001-07-20 2003-02-06 Schwaebische Huettenwerke Gmbh Verfahren zur endkonturnahen Fertigung von Bauteilen bzw. Halbzeugen aus schwer zerspanbaren Leichtmetalllegierungen, und Bauteil bzw. Halbzeug, hergestellt durch das Verfahren
DE102006043502B4 (de) * 2006-09-12 2008-11-27 Technische Universität Berlin Verfahren und Vorrichtung zum Herstellen eines gepreßten Stranges mittels Strangpressen

Family Cites Families (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DD9575A (de) *
DE753802C (de) * 1933-08-18 1953-05-26 Bosch Gmbh Robert Verfahren zur Herstellung von Massekernen, welche aus einzelnen Faeden oder Straengen eines Gemisches aus ferromagnetischem Pulver und isolierendem Bindemittel zusammengesetzt sind

Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3771221A (en) * 1971-12-03 1973-11-13 Bbc Brown Boveri & Cie Method and apparatus for producing fine-particle permanent magnets
WO1985001246A1 (en) * 1983-09-12 1985-03-28 Battelle Development Corporation Methods of compaction by incremental radial compression and/or low-ratio extrusion
US4521360A (en) * 1983-09-12 1985-06-04 Battelle Memorial Institute Methods of compaction by incremental radial compression and/or low-ratio extrusion
US4480453A (en) * 1983-12-09 1984-11-06 N P S P Po Hydroplastichna Obrabotka Na Metalite Apparatus for blast hydroplastic finishing of tubular billets
US5409662A (en) * 1992-02-08 1995-04-25 Hitachi Powdered Metals Co., Ltd. Method and apparatus for extruding powder material
CN106378361A (zh) * 2016-09-06 2017-02-08 南京理工大学 一种微型平面弹簧静液挤压的装置

Also Published As

Publication number Publication date
FR1569530A (de) 1969-05-30
GB1221879A (en) 1971-02-10
SE377434B (de) 1975-07-07
JPS5132564B1 (de) 1976-09-13
DE1758540B1 (de) 1972-03-09

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