EP0281591B1 - Procede, dispositif et capsule de fabrication de tubes ou de profiles allonges similaires par metallurgie des poudres - Google Patents

Procede, dispositif et capsule de fabrication de tubes ou de profiles allonges similaires par metallurgie des poudres Download PDF

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Publication number
EP0281591B1
EP0281591B1 EP87905747A EP87905747A EP0281591B1 EP 0281591 B1 EP0281591 B1 EP 0281591B1 EP 87905747 A EP87905747 A EP 87905747A EP 87905747 A EP87905747 A EP 87905747A EP 0281591 B1 EP0281591 B1 EP 0281591B1
Authority
EP
European Patent Office
Prior art keywords
capsule
powder
mandrel
tip
cover
Prior art date
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
EP87905747A
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German (de)
English (en)
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EP0281591A1 (fr
Inventor
Claes Tornberg
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Avesta Nyby Powder AB
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Avesta Nyby Powder AB
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Publication date
Application filed by Avesta Nyby Powder AB filed Critical Avesta Nyby Powder AB
Priority to AT87905747T priority Critical patent/ATE60262T1/de
Publication of EP0281591A1 publication Critical patent/EP0281591A1/fr
Application granted granted Critical
Publication of EP0281591B1 publication Critical patent/EP0281591B1/fr
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Expired - Lifetime legal-status Critical Current

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    • 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
    • B22F5/00—Manufacture of workpieces or articles from metallic powder characterised by the special shape of the product
    • B22F5/10—Manufacture of workpieces or articles from metallic powder characterised by the special shape of the product of articles with cavities or holes, not otherwise provided for in the preceding subgroups
    • 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
    • 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
    • B22F2998/00—Supplementary information concerning processes or compositions relating to powder metallurgy

Definitions

  • the invention relates to a method, a capsule and a device for the powder-metallurgical production of tubes or the like. Elongated profiles.
  • High-quality pipes can be produced by extrusion of the powder-metallurgical pipe blanks or compacts. Since it is not necessary to drill out to form the central longitudinal bore, the material losses usually present during drilling can be avoided.
  • the present invention is based on the object of improving the latter method in such a way that the compact required for extrusion is obtained with even less effort and with equally good or even better quality.
  • the precompaction of the powder within the capsule is preferably carried out by means of ultrasonic vibration in such a way that a powder density of approximately 70% of the theoretical density is obtained.
  • the capsule After the capsule has been closed, it is exposed to a preferably cold isostatic pressure acting on all sides in order to increase the powder density to about 95% of the theoretical density.
  • the capsule is then positioned in a pot-like receptacle in an extrusion system, in which it is perforated by means of a mandrel to form a central longitudinal bore.
  • the mandrel is provided at its free end with a tip made of extremely resistant material, in particular hard metal or ceramic.
  • the powder is pressed radially from the inside outwards, resulting in a particularly uniform density over the cross section of the capsule.
  • the capsule is perforated at an elevated temperature of e.g. B. 600 ° C or in the area of hot working or extrusion temperature, d. H. at a temperature of around 1,100 to 1,200 ° C.
  • the extrusion can immediately follow the perforation of the capsule.
  • the capsule to be punched can be manufactured significantly cheaper than the tubular capsules z. B. according to EP-A-20 536 or DE-A-24 19 014.
  • the mandrel is pressed into the powder-filled capsule to form the central bore or perforation, preferably by means of a vertical press, the mandrel, at least its tip, being supported with play in order to achieve high concentricity.
  • the mandrel tip mentioned is designed either as a cone or a truncated cone.
  • the capsule consists of an outer jacket 8 and a lid 9 each made of thin, ductile sheet metal and a somewhat thick-walled bottom 14, the peripheral edge 15 of which is reinforced, in the present case extending prismatically inwards, so that the inner region 10 of the Bottom 14 has a smaller thickness than the edge region.
  • Bottom and lid are welded to the outer jacket (ring welds 12, 25).
  • the cover could also be an integral part of the outer casing 8.
  • Outer jacket 8 and cover 9 would then preferably be formed using the deep-drawing process.
  • the end section of the outer casing 8 assigned to the cover 9 is drawn in radially inward to form a radially inwardly extending circumferential arch 11, along the inner edge of which the cover 9 is welded (weld seam 12).
  • the outer jacket 8 is first closed on the base side by a base plate 14.
  • the capsule is then filled with metal powder, preferably with pre-compression using ultrasonic vibration. This results in a powder density of up to about 70% of the theoretical density.
  • the capsule is then closed with the lid 9 and exposed to a cold isostatic pressure acting on all sides in order to increase the density of the powder on average to about 95% of the theoretical density, the density profile over the cross section of the capsule corresponding to curve 24 in FIG. 4 .
  • the powder density increases radially from the inside to the outside. This density curve is of great importance for the further action on the capsule as described below.
  • the metal powder filling is identified in FIG. 1 by the reference number 3.
  • the cold isostatically pressed capsule is then positioned in a pot-like receptacle 1 of a press, not shown in FIG. 2, into which a mandrel 4, 5 can be inserted centrally, forming a central capsule bore or hole 26.
  • the mandrel 4, 5 is assigned a central opening 2 in the bottom of the pot-like receptacle 1, into which the mandrel 4, 5 can be moved to form the aforementioned capsule perforation.
  • the press-in movement of the mandrel 4, 5 is indicated in FIG. 2 with the parts 27. Because the powder is least compressed in the area of the geometrical longitudinal axis 27 of the capsule, the mandrel 4, 5 can be pressed relatively easily into the capsule filled with powder.
  • the powder 3 is thereby subjected to an additional radial pressure from the inside to the outside with a simultaneous “pore closure” in the region of the central inner hole 26.
  • the compact produced by the described method using the described device can be directly extruded in a conventional manner to form a finished tube.
  • the mandrel 4, 5 is pressed in through the base 14, namely by breaking open the thin-walled inner region 10.
  • the capsule and the metal powder 3 located in the capsule also become an additional axial one Subjected to pressure, which leads to a slight deformation of the capsule, in particular in the region of the lid curvature 11 or 11 '. There the powder can evade with corresponding deformation of the outer jacket or lid.
  • the mandrel consists of a shaft 4 and a tip 5 arranged at the free end of the shaft 4, which tip is conical in the embodiment according to FIG. 2.
  • the tip 5 is loosely attached to the mandrel 4, which on the one hand gives a high degree of concentricity and on the other hand has the possibility of removing the tip 5 before the mandrel moves back into the starting position (against arrows 27), so that the mandrel moves back is not hindered by the tip 5.
  • This measure is particularly advantageous when the tip 5 - as shown in FIG. 2 and also in FIG. 5 - protrudes radially over the shaft 4 along its circumference.
  • the tip 5 consists of a high-strength material, in particular hot-work steel, hard metal or ceramic. According to FIGS. 2 and 5, the tip 5 or 5 'is rounded on its peripheral edge 13 or 13' which faces the shaft 4 and projects slightly above it. In the embodiment according to FIG. 5, the tip 5 ′ is designed in the manner of a truncated cone, in contrast to the conical configuration of the tip 5 in the embodiment according to FIG. 2.
  • the tip 5 or 5 'and optionally also the shaft 4 are preferably provided with a lubricant, in particular in the form of a stocking 6 made of glass fiber material placed over the tip 5 or 5' and optionally also the shaft 4.
  • a lubricant in particular in the form of a stocking 6 made of glass fiber material placed over the tip 5 or 5' and optionally also the shaft 4.
  • Glass as a lubricant is particularly advantageous in so-called "hot punching", i.e. H. when the perforation 26 is formed at an elevated temperature. It is normally sufficient to provide only the tip 5 or 5 'with a cap made of glass fiber material.
  • the shaft 4 is preferably also lubricated, e.g. B. in the form of a glass fiber layer.
  • the mandrel or the shaft 4 of the same is mounted so as to be longitudinally displaceable within a guide sleeve 7 of the press (not shown in more detail in FIG. 2).
  • the mandrel 4, 5 is driven preferably hydraulically in a manner known per se.
  • Fig. 3 possible modifications of the powder capsule are shown schematically.
  • the embodiment with the lid 9 'curved at the edge has already been described in connection with the embodiment according to FIG. 1.
  • the cover can also be designed as a relatively thick, rigid plate 9 ′′ which is welded to the associated end peripheral edge of the outer casing 8 (ring weld seam 28).
  • the bottom 14 can be formed by a plate 23 which has a central recess 19 on the outside, with a corresponding reduction in the thickness of the bottom in this area.
  • This embodiment corresponds in terms of its effect to that of FIG. 1 only with the difference that the recess 19 is arranged on the outside, while in the embodiment of FIG. 1 it is on the inside.
  • bottom 14 is characterized by a relatively thick ring 16, the central opening of which is closed on the inside of the capsule by a thin-walled plate 17, so that overall a configuration similar to the bottom plate 23 with an outside recess 19 is created.
  • the plate 17 is welded to the end face of the ring 16 inside the capsule (weld seam 29).
  • the end sections 18 of the outer casing 8 are each designed to taper conically.
  • the space created thereby within the pot-shaped recess 1 is filled when the capsule is punched by corresponding expansion of the capsule.
  • the capsule can expand into this free space.
  • the conically tapering end sections 18 are no longer recognizable on the finished compact.
  • the bottom 14 can of course be made similar to the cover 9 or 9 'from the same sheet as the outer jacket 8. However, it has been shown that it is easier and safer in terms of the tightness of the capsule to weld thick-walled covers. For easier perforation of the capsule, however, the covers should then be made as thin-walled as possible in the central region, so that they can be broken open and penetrated more easily by the mandrel 4, 5. Accordingly, it is advantageous if the cover 9 'in FIG. 3 also has a configuration similar to that of the base plates 22, 23 or the base plate according to FIG. 1.
  • a capsule with an outer diameter of 222 mm and a length of 700 mm and a wall thickness of 2 mm was filled with 18/8 stainless powder.
  • the capsule was closed at one end with a 30 mm thick base plate, the central area of which had a recess with a depth of approximately 25 mm.
  • the diameter of the recess was 104 mm.
  • the plate thickness in the area of the recess was therefore 5 mm; this had to be pierced by the punch.
  • the capsule was cold isostatically pressed at a pressure of 4000 bar.
  • the capsule After heating to 1,150 ° C, the capsule was punched in a vertical press.
  • the compact obtained was characterized by a good inner surface and an eccentricity of the central perforation of less than 4 mm.
  • the compact was extruded into a tube with the dimensions: 140x12 mm.
  • the tube was characterized by both a good inner and a good outer surface quality, a homogeneous structure and good mechanical properties.

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  • Engineering & Computer Science (AREA)
  • Manufacturing & Machinery (AREA)
  • Mechanical Engineering (AREA)
  • Powder Metallurgy (AREA)

Abstract

Un procédé et un dispositif sont utilisés pour fabriquer des tubes ou des profilés allongés similaires par métallurgie des poudres. On remplit une capsule à parois minces avec un métal et/ou un alliage métallique en poudre, le cas échéant après avoir comprimé au préalable la poudre par vibration ou par un procédé similaire. On ferme ensuite la capsule et on la comprime à froid et/ou à chaud par une pression isostatique appliquée de tous côtés et le comprimé ainsi obtenu est soumis à des traitements supplémentaires, en particulier l'extrusion. Afin de former un comprimé tubulaire, on perfore centralement (alésage 26) la capsule remplie de poudre (3) avec un poinçon (4, 5), tout en comprimant radialement la poudre de l'intérieur vers l'extérieur, une fois que la capsule a été fermée (couvercle 9; 9'; 9'') et soumise à la pression isostatique. La capsule est composée d'une enveloppe cylindrique extérieure (8), d'un fond (14) et d'un couvercle (9; 9'; 9'').

Claims (17)

1. Procédé de fabrication par métallurgie des poudres de tubes ou profilés analogues, dans lequel on charge une capsule à parois minces de poudre de métal et/ou d'alliages métalliques -le cas échéant avec prédensification au moyen de vibrations ou analogue-, on ferme ensuite cette capsule et on la presse à froid et/ou à chaud au moyen d'une pression isostatique s'exerçant de tous côtés, et on poursuit le façonnage de l'ébauche pressée obtenue, en particulier par extrusion, caractérisé en ce que la capsule garnie de poudre, pour la formation d'une ébauche pressée tubulaire, est percée de façon centrale au moyen d'un mandrin, après la fermeture et le pressage isostatique, avec pressage correspondant de la poudre radialement de l'intérieur vers l'extérieur.
2. Procédé selon la revendication 1, caractérisé en ce que le perçage de la capsule est effectué à température élevée, en particulier environ 600°C, de préférence environ 1100 à 1200°C.
3. Procédé selon l'une des revendications 1 et 2, caractérisé en ce qu'on positionne la capsule en vue du perçage dans un récipient en forme de godet dont le fond présente une ouverture centrale pour le passage du mandrin ou analogue.
4. Procédé selon l'une des revendications 1 à 3, caractérisé en ce qu'on densifie la poudre par la prédensification à une densité d'environ 70% de la densité théorique.
5. Procédé selon l'une des revendications 1 à 4, caractérisé en ce qu'on densifie la poudre par le pressage isostatique à une densité moyenne d'environ 80 à 95% de la densité théorique.
6. Procédé selon l'une des revendications 1 à 5, caractérisé en ce que le perçage de la capsule intervient en utilisant un lubrifiant, en particulier sous forme de verre.
7. Capsule, en particulier pour la mise en oeuvre du procédé selon une ou plusieurs des revendications 1 à 6, caractérisée en ce qu'elle comporte une paroi latérale extérieure (8) ainsi qu'un couvercle (9; 9') chacun en tôle mince ductile ainsi qu'un fond (14) qui présente au moins un bord périphérique (15) renforcé plus épais.
8. Capsule selon la revendication 7, caractérisée en ce que le couvercle (9; 9'), la paroi latérale extérieure (8) et le fond (14) sont liés les uns aux autres par soudage (cordons de soudure 12, 25).
9. Capsule selon la revendication 7, caractérisée en ce que le couvercle (9; 9') fait partie intégrante de la paroi latérale extérieure (8).
10. Capsule selon l'une des reveendications 7 à 9, caractérisée en ce que la paroi latérale extérieure (8) présente des portions d'extrémité (18) qui se rétrécissent chacune en cône.
11. Capsule selon l'une des revendications 7 à 10, caractérisée en ce que la portion d'extrémité de la paroi latérale extérieure (8) associée au couvercle (9) est courbée radialement vers l'intérieur (courbure périphérique 11), ou que le couvercle (9') présente un bord périphérique (11') courbé en direction de la paroi latérale extérieure (8).
12. Capsule selon l'une des revendications 7 à 11, caractérisée en ce que le fond (14) est formé d'une plaque métallique relativement épaisse, de préférence d'environ 10 à 30 mm, dont la région centrale (10) comporte sur sa face intérieure ou sur sa face extérieure un évidement conduisant à une épaisseur réduite en conséquence du fond dans cette région d'environ 3 à 7, en particulier environ 5 mm.
13. Capsule selon l'une des revendications 7 à 12, caractérisée en ce que le couvercle est formé, au lieu d'une tôle mince ductile, comme le fond (14) d'une plaque métallique (9") relativement épaisse, qui peut comporter de même que le fond, sur sa face intérieure et/ou sa face extérieure, un évidement réduisant l'épaisseur du fond.
14. Installation pour la mise en oeuvre du procédé selon l'une des revendications 1 à 6, composée d'une capsule selon l'une des revendications 7 à 13 et d'un logement (1) en forme de godet pour la capsule et d'un mandrin (4, 5) pouvant être enfilé de façon centrale dans le logement en forme de godet (1) et associé à une ouverture (2) disposée en correspondance de façon centrale dans le fond du logement en forme de godet.
15. Installation selon la revendication 14, caractérisée en ce que le mandrin comprend une pointe (5 ou 5') de forme conique ou tronconique en matériau à haute résistance, en particulier acier pour travail à chaud, métal dur ou céramique, la pointe (5; 5') étant de préférence montée de façon lâche à l'extrémité libre d'une tige (4) mobile alternativement et dépassant légèrement de celle-ci en direction radiale le long de son périmètre.
16. Installation selon la revendication 15, caractérisée en ce que le bord périphérique (13; 13') de la pointe (5; 5') tourné vers la tige (4) et dépassant légèrement de celle-ci est arrondi.
17. Installation selon l'une des revendications 14 à 16, caractérisée en ce que la pointe (5; 5') et le cas échéant aussi la tige (4) du mandrin de perçage sont munies de lubrifiant, en particulier sous forme d'une gaine (6) en fibres de verre enfilée sur la pointe (5; 5') et le cas échéant aussi sur la tige (4).
EP87905747A 1986-09-03 1987-09-03 Procede, dispositif et capsule de fabrication de tubes ou de profiles allonges similaires par metallurgie des poudres Expired - Lifetime EP0281591B1 (fr)

Priority Applications (1)

Application Number Priority Date Filing Date Title
AT87905747T ATE60262T1 (de) 1986-09-03 1987-09-03 Verfahren, vorrichtung und kapsel zur pulvermetallurgischen herstellung von rohren oder dgl. langgestreckten profilen.

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
SE8603686 1986-09-03
SE8603686A SE8603686D0 (sv) 1986-09-03 1986-09-03 Halning

Publications (2)

Publication Number Publication Date
EP0281591A1 EP0281591A1 (fr) 1988-09-14
EP0281591B1 true EP0281591B1 (fr) 1991-01-23

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EP87905747A Expired - Lifetime EP0281591B1 (fr) 1986-09-03 1987-09-03 Procede, dispositif et capsule de fabrication de tubes ou de profiles allonges similaires par metallurgie des poudres

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Country Link
US (1) US4935198A (fr)
EP (1) EP0281591B1 (fr)
JP (1) JPS63502840A (fr)
SE (1) SE8603686D0 (fr)
WO (1) WO1988001547A1 (fr)

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SE501390C2 (sv) * 1989-06-01 1995-01-30 Abb Stal Ab Sätt för framställning av ett kompoundrör med ett slitstarkt yttre skikt
JP2008231483A (ja) * 2007-03-19 2008-10-02 Nikkeikin Aluminium Core Technology Co Ltd 粉末合金圧延用ケース
US8376726B2 (en) * 2009-08-20 2013-02-19 General Electric Company Device and method for hot isostatic pressing container having adjustable volume and corner
US8303289B2 (en) * 2009-08-24 2012-11-06 General Electric Company Device and method for hot isostatic pressing container
US9267184B2 (en) 2010-02-05 2016-02-23 Ati Properties, Inc. Systems and methods for processing alloy ingots
US8230899B2 (en) 2010-02-05 2012-07-31 Ati Properties, Inc. Systems and methods for forming and processing alloy ingots
US10207312B2 (en) 2010-06-14 2019-02-19 Ati Properties Llc Lubrication processes for enhanced forgeability
GB201015267D0 (en) * 2010-09-14 2010-10-27 Rolls Royce Plc An object forming assembly
US8789254B2 (en) 2011-01-17 2014-07-29 Ati Properties, Inc. Modifying hot workability of metal alloys via surface coating
US9199308B2 (en) 2011-09-20 2015-12-01 GM Global Technology Operations LLC Method of producing composite articles and articles made thereby
US9120150B2 (en) * 2011-12-02 2015-09-01 Ati Properties, Inc. Endplate for hot isostatic pressing canister, hot isostatic pressing canister, and hot isostatic pressing method
US9027374B2 (en) 2013-03-15 2015-05-12 Ati Properties, Inc. Methods to improve hot workability of metal alloys
US9539636B2 (en) 2013-03-15 2017-01-10 Ati Properties Llc Articles, systems, and methods for forging alloys
RU2551750C1 (ru) * 2013-12-24 2015-05-27 федеральное государственное автономное образовательное учреждение высшего профессионального образования "Национальный исследовательский ядерный университет МИФИ" (НИЯУ МИФИ) Способ изготовления трубных заготовок из металлических порошков

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DE3205158C1 (de) * 1982-02-13 1983-08-25 MTU Motoren- und Turbinen-Union München GmbH, 8000 München Kapsel fuer das heissisostatische Pressen von hochbeanspruchten und kompliziert geformten Werkstuecken fuer Turbomaschinen
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US4722825A (en) * 1987-07-01 1988-02-02 The United States Of America As Represented By The Secretary Of The Navy Method of fabricating a metal/ceramic composite structure

Also Published As

Publication number Publication date
EP0281591A1 (fr) 1988-09-14
JPS63502840A (ja) 1988-10-20
SE8603686D0 (sv) 1986-09-03
JPH031361B2 (fr) 1991-01-10
WO1988001547A1 (fr) 1988-03-10
US4935198A (en) 1990-06-19

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