DK160680B

DK160680B - METHOD AND APPARATUS FOR HOT COMPRESSION OF POWDER MATERIAL

Info

Publication number: DK160680B
Application number: DK400583A
Authority: DK
Inventors: Walter J Rozmus
Original assignee: Dow Chemical Co
Priority date: 1982-09-20
Filing date: 1983-09-02
Publication date: 1991-04-08
Also published as: NO164080B; DK160680C; DE3375286D1; AU3982585A; EP0105653B1; CA1222152A; DK400583A; AU3982685A; AR231811A1; AU561135B2; NO164080C; DK400583D0; MX156866A; AU545852B2; ATE31886T1; NO833160L; EP0105653A1; JPS6239201B2; AU1896983A; BR8305054A

Description

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iin

Opfindelsen angår en fremgangsmåde af den i krav l's indledning angivne art. Omdannelse af pulvermateriale til faste masser udføres sædvanligvis ved, at en beholder evakueres og fyldes med pulvermaterialet, hvorefter be-5 holderen lukkes hermetisk. Den fyldte og hermetisk lukkede beholder udsættes så for tryk. Typisk tilføres der også varme for at opvarme pulveret til en fortætningstemperatur. Kombinationen af varme og tryk gør det nemmere at fortætte pulveret.The invention relates to a method of the kind set out in the preamble of claim 1. Conversion of powder material to solid masses is usually carried out by evacuating and filling a container with the powder material, after which the container is hermetically sealed. The filled and hermetically sealed container is then subjected to pressure. Typically, heat is also applied to heat the powder to a condensing temperature. The combination of heat and pressure makes it easier to densify the powder.

1010

Det er kendt at anbringe en med pulver fyldt, hermetisk lukket beholder i en autoklave eller i en varm, isosta-tisk presse, hvor den udsættes for varme og gastryk.It is known to place a powder-filled, hermetically sealed container in an autoclave or in a hot, isostatic press, where it is exposed to heat and gas pressure.

15 På grund af omkostningerne og begrænsningerne ved autoklaver eller varme isostatiske presser er der sket en betydelig udvikling af metoder, hvor det pulver, der skal fortættes, indkapsles i en i det væsentlige fast og usam-mentrykkelig beholder, der således danner et trykoverfør-20 ende medium, der ved manipulation ved omgivelsestemperaturer og ved de høje kompressionstemperaturer er formfast, men som ved tryk på hele den ydre overflade bliver flydende og i stand til at flyde plastisk således, at pulveret komprimeres hydrostatisk. Pulveret indkapsles 25 typisk hermetisk i det trykoverførende medium, der derefter opvarmes til en temperatur, der er tilstrækkelig til komprimering og fortætning af pulveret. Efter tilstrækkelig opvarmning anbringes det trykoverførende medium med pulveret imellem to kæber i en presse, der lukkes hur-30 tigt, så at hele det trykoverførende mediums ydre overflade påføres tryk. Det trykoverførende medium må, i det mindste umiddelbart før en forudvalgt fortætningsgrad, være fuldstændig tæt, ukomprimerbart og i stand til at flyde, så at det til pulveret overførte tryk er hydrosta-35 tisk og derfor påtrykkes fra alle retninger, dvs. ikke-retningsbestemt. Efter at materialet er fortættet til den ønskede grad, må det trykoverførende medium, der afgræn-Due to the cost and limitations of autoclaves or hot isostatic presses, there has been considerable development of methods in which the powder to be condensed is encapsulated in a substantially solid and incompressible container thus forming a pressure transfer 20 end medium which, by manipulation at ambient temperatures and at high compression temperatures, is solid but which, upon pressure over the entire outer surface, becomes fluid and capable of flowing plastically so that the powder is hydrostatically compressed. The powder is typically hermetically encapsulated in the pressure transfer medium which is then heated to a temperature sufficient for compacting and densifying the powder. After sufficient heating, the pressure-transmitting medium with the powder between two jaws is placed in a press which is rapidly closed so that pressure is applied to the entire surface of the pressure-transmitting medium. The pressure transmitting medium must be at least immediately prior to a preselected densification, completely dense, uncompressible and capable of flowing so that the pressure transmitted to the powder is hydrostatic and therefore applied from all directions, i.e. non-directional. After the material is densified to the desired degree, the pressure-transmitting medium defining

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2 ser beholderen, fjernes fra det fortættede materiale, hvorved dets integritet går tabt. Det trykoverførende medium er således enten ikke længere anvendeligt eller må gennemgå omfattende processer til frembringelse af en ny 5 beholder.2, the container is removed from the condensed material, thereby losing its integrity. Thus, the pressure-transmitting medium is either no longer useful or must undergo extensive processes to produce a new container.

Opfindelsen har til formål at angive en fremgangsmåde af den omhandlede art, som gør det muligt at genanvende det trykoverførende medium, så at det samme medium kan an-10 vendes til fremstilling af flere fortættede emner.The invention has for its object to provide a process of the kind which makes it possible to reuse the pressure-transmitting medium so that the same medium can be used for the production of several densified articles.

Dette formål opnås ved, at fremgangsmåden udføres som angivet i krav l’s kendetegnende del, idet det elastomere medium ved denne udførelse beskyttes mod at blive ødelagt 15 af varmen, og derfor kan genanvendes flere gange.This object is achieved by performing the method as set forth in claim 1, wherein the elastomeric medium in this embodiment is protected from being destroyed by heat, and therefore can be reused several times.

Opfindelsen angår også et apparat til udøvelse af fremgangsmåden og af den i krav 13's indledning angivne art, og det ejendommelige ved apparatet ifølge opfindelsen er 20 angivet i krav 13's kendetegnende del.The invention also relates to an apparatus for carrying out the method and of the nature specified in the preamble of claim 13, and the characteristic of the apparatus according to the invention is indicated in the characterizing part of claim 13.

Hensigtsmæssige enkeltheder ved fremgangsmåden og apparatet ifølge opfindelsen er angivet i underkravene 2-12 og 14-24.Suitable details of the method and apparatus of the invention are set forth in subclaims 2-12 and 14-24.

2525

Opfindelsen skal nu beskrives nærmere med henvisning til tegningen, på hvilken: fig. 1 er et tværsnit af en udførelses form for apparatet 30 ifølge opfindelsen i åben stilling.The invention will now be described in more detail with reference to the drawing, in which: FIG. 1 is a cross-sectional view of an embodiment of the apparatus 30 according to the invention in the open position.

fig. 2 et tværsnit af et apparat i lukket stilling, fig. 3 et snit efter linien 3-3 i fig. 2, og 35 fig. 4 viser en del af den ydre overflade af en pakning, der anvendes i apparatet ifølge opfindelsen.FIG. 2 is a cross-sectional view of an apparatus in a closed position; FIG. 3 is a sectional view taken along line 3-3 of FIG. 2, and FIG. 4 shows a portion of the outer surface of a gasket used in the apparatus of the invention.

33

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Den foreliggende opfindelse kan anvendes til at omdanne forskellige metalliske eller ikke-metalliske pulvere, såvel som kombinationer heraf, til faste masser. Pulverets tæthed øges til en forudbestemt, eller ønsket tæthed, som 5 kan være den fulde tæthed, eller en mindre grad af tæthed. Den fortættede masse fremstilles af materiale, der har en mindre vægtfylde end den forudbestemte slutvægt-fylde, og som indkapsles i et trykoverførende medium, som påføres tryk på hele den ydre overflade for at frembringe 10 en forudbestemt fortætning af det indkapslede materiale ved det hydrostatiske tryk, der påføres mediet, idet mediet er tilnærmelsesvis helt tæt og ikke-komprimerbart og i stand til at flyde elastisk i det mindste umiddelbart før den forudbestemte, fortætningsgrad. Med andre ord 15 overfører mediet tryk hydrostatisk på samme måde som en væske, dvs. fra alle retninger omkring materialet, så at dette fortættes.The present invention can be used to convert various metallic or non-metallic powders, as well as combinations thereof, into solid masses. The density of the powder is increased to a predetermined or desired density, which may be the full density, or a lesser degree of density. The densified mass is made of material having a density less than the predetermined final weight density and encapsulated in a pressure transfer medium which exerts pressure on the entire outer surface to produce a predetermined densification of the encapsulated material at the hydrostatic pressure. applied to the medium, the medium being approximately completely dense and non-compressible and capable of flowing elastically at least immediately prior to the predetermined degree of densification. In other words, the medium transfers pressure hydrostatically in the same way as a liquid, i.e. from all directions around the material so that it is densified.

Der henvises nu til fig. 1. En mængde ikke helt fortættet 20 pulver 10 udfylder og er indkapslet i en beholder 12. Beholderen 12 evakueres gennem et rør (ikke vist) og fyldes så med pulveret 10 under vakuum gennem røret. Efter fyldningen forsegles røret, så at beholderen 12 med pulveret 10 bliver hermetisk lukket med pulveret under vakuum. Be-25 holderen 12 er tyndvægget og fortrinsvis fremstillet af tyndt metalmateriale. Beholderen 12 kan fyldes og forsegles ved den i USA patentskrift nr. 4 229 872 beskrevne fremgangsmåde.Referring now to FIG. 1. An amount of not fully densified 20 powder 10 fills and is encapsulated in a container 12. The container 12 is evacuated through a tube (not shown) and then filled with the powder 10 under vacuum through the tube. After filling, the tube is sealed so that the container 12 with the powder 10 is hermetically sealed with the powder under vacuum. The container 12 is thin-walled and preferably made of thin metal material. The container 12 can be filled and sealed by the method described in U.S. Patent No. 4,229,872.

30 Beholderen 12 er cirkulær i tværsnit og danner således en cylinder, og den har et fylderør (ikke vist), der strækker sig fra den ene ende. Det forstås, at udformningen af beholderen 12 vil afhænge af den ønskede udformning for det endelige emne.The container 12 is circular in cross section and thus forms a cylinder and has a filling tube (not shown) extending from one end. It is understood that the design of the container 12 will depend on the desired design for the final workpiece.

3535

Som det fremgår af fig. 1 har aggregatet en matrice 14 og en patrice 16 med fastgørelsesorganer 18 til fastgørelseAs shown in FIG. 1, the assembly has a die 14 and a die 16 with fastening means 18 for fastening

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af opretningselementer, således at matricen 14 og patri-cen 16 kan ind jus teres i forhold til hinanden. Matricen 14 og patricen 16 har også udboringer 20 til anbringelse af fastgørelsesbolte eller tappe, hvormed matricen 14 og 5 patricen 16 kan fastgøres til en presse, som kan være af enhver kendt art. Patricen 16 og matricen 14 bevæger sig ved pressens åbning og lukning mellem en åben stilling vist i fig. 1, og den lukkede stilling vist i fig. 2.of rectifying elements so that the matrix 14 and the matrix 16 can be adjusted relative to each other. The die 14 and die 16 also have bores 20 for attaching fastening bolts or pins, by which die 14 and 5 the die 16 can be attached to a press which may be of any known kind. The die 16 and die 14 move at the press opening and closing between an open position shown in FIG. 1, and the closed position shown in FIG. 2nd

10 Et trykoverførende medium, der består af en første og en anden elastomer del 22 og 24, afgrænser et hulrum til omslutning af det materiale, der skal fortættes. Matricen 14 er lavet af et usammentrykkeligt materiale såsom stål og indeholder et matricehulrum 26. Også patricen 16 er 15 lavet af et usammentrykkeligt materiale såsom stål og indeholder et patricehulrum 28. Patricen 16 har en forhøjning eller fremspringende del 30 omkring patricehul-rummet 28. Matricehulrummet 26 har tilsvarende periferiflader, der kan modtage og komme i glidekontakt med de 20 udvendige overflader af den fremspringende del 30 på patricen 16. Med andre ord er de indre overflader af matricen 14’s hulrum 26 positioneret sådan i forhold til de udvendige sider af fremspringet 30 på patricen 16, at de kommer i tæt glidende forbindelse med hinanden, når 25 matricen 14 og patricen 16 lukkes. Det elastomere mediums første del 22 fastholdes i matricehulrummet 26 ved at være kilet fast deri eller ved, at små mængder af et klæbemiddel fastholder den elastomere komponent i hulrummet 26. Den anden elastomere del 24 fastholdes på lignen-30 de måde i patricehulrummet 28. Den første og den anden elastomere del 22 og 24 afgrænser et cylindrisk hulrum, der omgiver det materiale, 10, der skal komprimeres. De elastomere dele 22 og 24 kan ud over naturligt gummi bestå af elastomere, såsom neopren, polysiloxanelastomere, > 35 polyurethan, polysvovlgummi, polybutadien, buna-S etc.A pressure transmitting medium consisting of a first and second elastomeric portions 22 and 24 defines a cavity for enclosing the material to be densified. The die 14 is made of an incompressible material such as steel and contains a die cavity 26. Also the die 16 is made of an incompressible material such as steel and contains a die cavity 28. The die 16 has an elevation or protruding portion 30 around the die cavity 28. 26 has corresponding peripheral surfaces which can receive and slip into contact with the 20 outer surfaces of the protruding portion 30 of the die 16. In other words, the inner surfaces of the cavity 26 of the die 14 are positioned such as with the outer sides of the projection 30 on the the die 16 that they come into close sliding relationship with each other when the die 14 and the die 16 are closed. The first part 22 of the elastomeric medium is retained in the die cavity 26 by being wedged therein or by small amounts of an adhesive retaining the elastomeric component in the cavity 26. The second elastomeric portion 24 is similarly retained in the die cavity 28. The first and second elastomeric portions 22 and 24 define a cylindrical cavity surrounding the material 10 to be compressed. The elastomeric parts 22 and 24 may, in addition to natural rubber, consist of elastomers such as neoprene, polysiloxane elastomers,> 35 polyurethane, polysulfur rubber, polybutadiene, buna-S etc.

Det elastomere medium, der danner delene 22 og 24, er ? elastisk på en sådan måde, at det kan komprimeres og al- j i 5The elastomeric medium forming parts 22 and 24 is? elastic in such a way that it can be compressed and al- j in 5

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ligevel vender tilbage til sin oprindelige form. Når det elastiske medium, der danner delene 22 og 24, komprimeres til en vis grænse, bliver det imidlertid tilnærmelsesvis ukomprimerbart, men alligevel flydende, dvs. i stand til 5 at flyde elastisk, så at det, når den ønskede fortætningsgrad af pulveret 10 nås, trykker hydrostatisk fra alle retninger på beholderen 12, hvorved pulveret 10 fortættes. Beholderen 12 er fremstillet af et tyndvægget materiale, og dens volumen reduceres til fortætning af 10 pulveret 10.yet returns to its original form. However, when the elastic medium forming the portions 22 and 24 is compressed to a certain limit, it becomes approximately incompressible, yet fluid, ie. capable of flowing elastically so that, when the desired densification of the powder 10 is reached, it hydrostatically presses from all directions on the container 12, thereby condensing the powder 10. The container 12 is made of a thin-walled material and its volume is reduced to densify the powder 10.

Pulveret 10 opvarmes til en høj temperatur, hvorved fortætningen af pulveret gøres nemmere. For at beskytte de elastomere, der udgør delene 22 og 24, danner varmeisole-15 rende barriereorganer en termisk barriere mellem pulver materialet 10 og de elastomere medier 22 og 24, før der føres tryk til medierne 22 og 24 ved lukning af matricen 14 og patricen 16, så at varmeoverførsel mellem materialet 10 og de elastomere medier 24 og 22 begrænses. De 20 termisk isolerende barriereorganer består af en første varmeisolerende kapsel 32, der fuldstændig omsluttet beholderen 12 for at begrænse varmetabet fra materialet 10, og en anden varmeisolerende kapsel 34, der omgiver den første kapsel 32 for at beskytte de elastomere dele 24 og 25 22 mod den varme, der strømmer fra den første kapsel 32.The powder 10 is heated to a high temperature, thereby facilitating the densification of the powder. To protect the elastomers constituting the portions 22 and 24, thermal insulating barrier means form a thermal barrier between the powder material 10 and the elastomeric media 22 and 24 before applying pressure to media 22 and 24 upon closing of die 14 and the die. 16 so that heat transfer between the material 10 and the elastomeric media 24 and 22 is restricted. The 20 thermally insulating barrier means consist of a first heat insulating capsule 32 which completely encloses the container 12 to limit the heat loss from the material 10, and a second heat insulating capsule 34 surrounding the first capsule 32 to protect the elastomeric portions 24 and 25 22. the heat flowing from the first capsule 32.

Kapslerne 32 og 34 er fremstillet af et keramisk materiale med lav termisk ledningsevne. Dette materiale er fluidt eller kan flyde, i det mindste umiddelbart før den 30 ønskede fortætningsgrad for pulveret 10 nås, når det påvirkes med et hydrostatisk tryk gennem de elastomere dele 22 og 24. Til sammenligning kan det siges, at det materiale, kapslerne 32 og 34 er fremstillet af, umiddelbart før den endelige fortætning flyder på samme måde som 35 kviksand. Ved den foretrukne udførelsesform støbes den første kapsel 32 omkring beholderen 12 i en form, så at kapslen 32 helt omslutter beholderen 12 og er af homogentThe capsules 32 and 34 are made of a low thermal conductivity ceramic material. This material is fluid or can flow, at least immediately before the desired condensation degree of the powder 10 is reached when it is actuated with a hydrostatic pressure through the elastomeric portions 22 and 24. By comparison, it can be said that the material, the capsules 32 and 34 is made of immediately before the final condensation flows in the same way as 35 mercury. In the preferred embodiment, the first capsule 32 is molded around the container 12 in a mold so that the capsule 32 completely encloses the container 12 and is of homogeneous

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6 materiale. Den første kapsel 32 med beholderen 12 opvarmes til en fortætning tilstrækkelig temperatur. Ved opvarmningen opvarmes kappen 32. Derefter anbringes kappen 32 med beholderen 12 i den anden kappe 34 i det hulrum, 5 der af grænses af de elastomere dele 22 og 24. Den anden kapsel 34 er udformet som to komplementære dele, der passer sammen således, at den første kapsel omsluttes helt.6 material. The first capsule 32 with the container 12 is heated to a densely sufficient temperature. Upon heating, the sheath 32. The sheath 32 is then heated with the container 12 in the second sheath 34 in the cavity 5 bounded by the elastomeric portions 22 and 24. The second sheath 34 is formed as two complementary portions, thus fitting together. that the first capsule is completely enclosed.

Den anden kapsel 34 er også fluid eller i stand til at flyde, umiddelbart før den ønskede fortætningsgrad af 10 pulveret 10 nås. Når det opvarmede materiale i beholderen 12, der er anbragt i den første kapsel 32, anbringes i den anden kapsel 34 som vist i fig. 1, lukkes pressen, så at matricen 14 og patricen 16 lukkes, hvorved fremspringet 30 på patricen 16 går ind i hulrummet 26 i matricen 15 14. Det er vigtigt at bemærke, at fremspringet 30 går ind i hulrummet 26 i matricen 14, før de elastomere dele 22 og 24 kommer i kontakt med hinanden og komprimeres for at skabe et hydrostatisk tryk, når de bliver ukomprimerbare og fluide, således at trykket overføres hydrostatisk gen-20 nem kapslen 32 og beholderen 12 og komprimerer og fortætter metalpulveret 10. For at kompensere for forskelle i termiske udvidelseskoefficienter kan enten den ene af eller begge kapslerne 32 og 34. Med andre ord kan enten den ene eller den anden af kapslerne 32 eller 34 have fibre 25 fordelt i sig til forstærkning. Yderligere kan kapslerne 32 eller 34 være udført i et sprødt materiale, der kan knuses og således blive ukomprimerbart, men alligevel fluidt nok til at overføre trykket hydrostatisk fra de elastomere dele 22 og 24 til beholderen 12 og dermed til 30 metalpulveret 10.The second capsule 34 is also fluid or capable of flowing immediately before the desired densification of the powder 10 is reached. When the heated material in the container 12 disposed in the first capsule 32 is placed in the second capsule 34 as shown in FIG. 1, the press is closed so that the die 14 and the die 16 are closed, whereby the projection 30 of the die 16 enters the cavity 26 of the die 15 14. It is important to note that the projection 30 enters the cavity 26 of the die 14 before elastomeric parts 22 and 24 come into contact with each other and are compressed to create a hydrostatic pressure as they become incompressible and fluid, so that the pressure is transferred hydrostatically through the capsule 32 and the container 12 and compresses and densifies the metal powder 10. To compensate for differences in thermal expansion coefficients, either one or both of the capsules 32 and 34. In other words, either one or the other of the capsules 32 or 34 may have fibers 25 distributed within themselves for reinforcement. Further, the capsules 32 or 34 may be made of a brittle material which can be crushed and thus become uncompressible, yet fluid enough to transfer the pressure hydrostatically from the elastomeric portions 22 and 24 to the container 12 and thus to the metal powder 10.

Det er vigtigt, at matricen 14's fremspring 30 træder ind i hulrummet 26 i patricen 16, før de elastomere dele 22 og 24 kommer i kontakt med hinanden, for at styre bevæg-35 elsen af de elastomere dele 22 og 24. Af yderligere hensyn til dette er der anbragt en pakning 36 af et hårdere materiale end de elastomere medier, der danner delene 22 7Importantly, the protrusion 30 of the die 14 enters the cavity 26 of the die 16 before the elastomeric portions 22 and 24 come into contact with each other to control the movement of the elastomeric portions 22 and 24. For further consideration, this is provided a gasket 36 of a harder material than the elastomeric media forming the parts 22 7

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og 24, i og under den øvre kant af hulrummet 26 1 patri-een 16 således, at pakningen, når fremspringet 30 på pa-tricen 16 går ind i matricen 14 og fører tryk til de elastomere dele 22 og 24, tvinges ind i et tætnende anlæg 5 mod de indre overflader af hulrummet 26 i matricen 14 ved overgangen mellem den ydre flade af fremspringet 30 og patricen 16 for at forhindre, at de elastomere medier 22 og 24 lækker ud mellem patricen 16 og matricen 14. Pakningen 36 er hårdere end de elastomere dele 22 og 24 og 10 kan derfor ikke flyde plastisk på samme måde, omend pakningsmaterialet 36 kan flyde plastisk.and 24, within and below the upper edge of the cavity 26 1 of the cartridge 16, such that when the projection 30 of the die 16 enters the die 14 and applies pressure to the elastomeric portions 22 and 24, it is forced into a sealing abutment 5 against the inner surfaces of the cavity 26 of the die 14 at the transition between the outer surface of the projection 30 and the die 16 to prevent the elastomeric media 22 and 24 from leaking between the die 16 and die 14. The seal 36 is harder than therefore, the elastomeric parts 22 and 24 and 10 cannot flow plastically in the same way, although the packing material 36 can flow plastically.

Når fremspringet 30 på patricen 16 træder ind i hulrummet 26 i matricen 14, kommer de elastomere dele 22 og 24 i 15 kontakt med hinanden og begynder at blive komprimeret til et punkt, hvor de bliver ukomprimerbare, og overfører tryk hydrostatisk på en ikke-retningsbestemt måde til sammentrykning af metalpulveret 10. Under den indledende komprimering af de elastiske dele 22 og 24 bevæger de sig 20 eller glider i forhold til overfladerne af de hulrum, i hvilke de er anbragt, i matricen 14 og patricen 16. Af hensyn til dette er delene 22 og 24 og pakningen 36 udstyret med et antal smøreriller 38 og 40 i de ydre overflader, således at bevægelsen i forhold til de nævnte 25 flader af hulrummene føres lettere. Fortrinsvis anbringes der er smøremiddel i rillerne 38 og 40. Som det fremgår af fig. 2, vil rillerne, når delene er fuldstændigt komprimeret, være så stærkt formindsket, at de næsten ikke kan ses. Rillerne eksisterer dog stadig og indeholder det 30 ukomprimerbare smøremiddel under den fulde kompression.As the protrusion 30 of the die 16 enters the cavity 26 of the die 14, the elastomeric portions 22 and 24 come into contact with each other and begin to be compressed to a point where they become uncompressible, applying hydrostatic pressure to a non-directional method of compressing the metal powder 10. During the initial compression of the elastic members 22 and 24, they move 20 or slide relative to the surfaces of the cavities in which they are placed in the die 14 and the die 16. For this reason, the portions 22 and 24 and the seal 36 are provided with a plurality of lubricating grooves 38 and 40 in the outer surfaces, so that movement relative to said 25 surfaces of the cavities is facilitated. Preferably, lubricant is applied to grooves 38 and 40. As can be seen from FIG. 2, when the parts are completely compressed, the grooves will be so greatly diminished that they can hardly be seen. However, the grooves still exist and contain the 30 uncompressible lubricant during full compression.

Metalpulveret 10 udfylder en tyndvægget beholder 12, der igen er anbragt i den første termisk isolerende kapsel 32 ved, at denne kapsel 32 er støbt omkring beholderen, 35 hvorefter kapsel og beholder opvarmes til en høj temperatur, der er tilstrækkelig til fortætning af pulveret 10. Derefter anbringes den nedre del af den anden kapsel 34 i 8The metal powder 10 fills a thin-walled container 12, which is again placed in the first thermally insulating capsule 32 in that this capsule 32 is molded around the container 35, after which the capsule and container are heated to a high temperature sufficient to densify the powder 10. Then, the lower portion of the second capsule 34 is placed in 8

DK 160680 BDK 160680 B

hulrummet 1 den elastomere del 22 i matricen 14, og den første kapsel 32 med pulveret anbringes 1 den ydre kapsels nedre del 34. Den øvre halvdel af den anden kapsel 34 anbringes da over den opvarmede Indre første kapsel 5 32, og matricen og patricen føres sammen til den stil ling, der er vist i fig. 2, for at fortætte og komprimere pulveret til en tæt masse 101. Det elastomere medium, der udgør delene 22 og 24, kan oprindeligt være komperimer-bart, men når det påførte tryk når et vist punkt, bliver 10 det ukomprimerbart, så at trykket overføres hydrostatisk på en ikke-retningsbestemt måde gennem kapslerne 32 og 34 til pulveret 10, således at dette pulver fortættes og komprimeres til den fortættede masse 10' med den ønskede fortætningsgrad. Matricen 14 og patricen 16 kan da åbnes, 15 således at de elastomere dele 22 og 24 kan vende tilbage til deres form, før de blev komprimeret, og kapslerne 32 og 34 kan fjernes, så at den faste masse 10' kan udtages. Kapslerne 32 og 34 vil normalt være til at smide væk, og nye kapsler skal anvendes, når matricen og patricen åbnes 20 og lukkes flere gange til dannelse af faste masser 10'.the cavity 1 of the elastomeric portion 22 of the die 14, and the first capsule 32 with the powder is placed in the lower portion 34. The upper half of the second capsule 34 is then placed over the heated Inner First capsule 5 32 and the die and die are passed. together to the position shown in FIG. 2, to densify and compress the powder to a dense mass 101. The elastomeric medium constituting the parts 22 and 24 may initially be compressible, but when the applied pressure reaches a certain point, it becomes incompressible so that the pressure is transferred hydrostatically in a non-directional manner through the capsules 32 and 34 to the powder 10 so that this powder is densified and compressed to the densified mass 10 'with the desired densification rate. The die 14 and die 16 can then be opened 15 so that the elastomeric parts 22 and 24 can return to their shape before being compressed and the capsules 32 and 34 can be removed so that the solid mass 10 'can be removed. The capsules 32 and 34 will normally be for throwing away, and new capsules should be used when the die and die are opened 20 and closed several times to form solid masses 10 '.

Det skal bemærkes, at det under visse omstændigheder kun er nødvendigt med én termisk isolerende kapsel mellem det opvarmede pulvermateriale 10 og de elastomere dele 22 og 25 24. Tykkelsen af de termisk isolerende organer kan vari ere afhængigt af størrelsen, udførelsen, vægten osv. af pulveret 10, der skal komprimeres og fortættes.It should be noted that in some circumstances only one thermally insulating capsule is required between the heated powder material 10 and the elastomeric portions 22 and 25 24. The thickness of the thermally insulating members may vary depending on the size, design, weight, etc. of the powder 10 to be compressed and densified.

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Claims

A method of hot compressing a powder material (10) of metallic or non-metallic constituents or combinations thereof to form a solid mass (10 ') of a predetermined density, wherein an amount of such material (10) with a lesser density than the predetermined, is heated and placed in a cavity in a pressure transfer medium (22, 24) applied to an outer pressure on the entire outer surface to produce the desired densification of the material by hydrostatic pressure from the medium (22, 24). ), the medium being approximately solid and incompressible and capable of flowing resiliently at least immediately prior to the predetermined densification, characterized in that an elastomeric pressure transfer medium is used and the material (10) is encapsulated in thermally insulating means ( 32, 34) in the cavity such that a thermal barrier is formed between the material 20 (10) and the elastomeric medium (22, 24) before applying medium pressure, to limit the heat transfer between the material (10) and the elastomeric medium (22, 24).

Process according to claim 1, characterized in that the material is encapsulated in thermally insulating means containing a first insulating capsule (32) to limit heat loss from the material (10) and containing a second insulating capsule (34) surrounding the first capsule. (32) to protect the elastomeric medium (22, 24) 30 from heat from the first capsule (32).

Method according to claim 2, characterized in that the material (10) in the first capsule (32) is heated and encapsulated before the first capsule (32) and material 35 (10) are placed in the second capsule (34) in the elastomeric medium (22, 24). DK 160680 B

Method according to claim 3, characterized in that the material (10) is encapsulated in a closed container (12) and then placed in the first capsule (32). 5

Method according to claim 4, characterized in that the first capsule (32) is molded around the container (12) such that the first capsule (32) forms a monolithic material.

Method according to claim 5, characterized in that the first capsule (32) is arranged in the second capsule (34), which is formed of a number of parts which fit together so as to surround the first capsule (32). 15

Process according to any one of claims 1-6, characterized in that thermally insulating means (32, 34) are used which are at least partially fluid and capable of flowing immediately before the predetermined seal.

Process according to any one of claims 1-6, characterized in that thermally insulating means (32, 34) are used which are at least partially reinforced with fibers.

A method according to any one of claims 1-6, characterized in that pressure is applied to the elastomeric medium (22, 24) by placing the elastomeric medium (22, 24) between a die (16) and a die ( 14) in a press.

Method according to any one of claims 1-6, characterized in that pressure is applied to the elastomeric medium (22, 24) by attaching a first part (22) of the elastomeric medium to a die cavity (26) and the second part (24) of the elastomeric medium is attached to a pair of trays (16) which can be moved into and out of the die cavity (26) in close sliding connection therewith, and that the first (22) ) and the second (24) elastomeric portion is positioned so that the die (16) enters the cavity (26) 5th die (14) before the first (22) and the second (24) elastomeric portion come into contact with each other and enclosing the thermal protective means (32, 34) in the cavity defined by the first (22) and second (24) portions of the elastomeric medium so that the first and second portions of the elastomeric medium can be opened and closed. by opening and closing the die (16) and die (14) in a press so that several densified items (10 ') can be produced successively .

A method according to claim 10, characterized in that a plurality of lubricating grooves (38) are formed in the surface of at least one of the parts (22, 24) of the elastomeric medium to facilitate the movement of the parts with respect to the cooperating surfaces of the die ( 16) or matrix 20 (14).

Method according to claim 10 or 11, characterized in that a gasket (36) of a harder material than the elastomeric medium (22) is placed in and 25 below the edge of the cavity (26) in the matrix (14), so that when the die (16) enters the die (14) and applies the elastomeric medium pressure, the gasket (36) will be forced into sealing abutment against the walls of the cavity (26) in the die (14) at the transition between it and the die 30 (16) to prevent the elastomeric medium (22) from leaking between the die (16) and the die (14).

Apparatus for hot densifying a powder material (10) consisting of metallic or non-metallic constituents 35 or combinations thereof to form a densified mass (10 ') with a predetermined density, wherein an amount of such material (10) containing has a smaller density than the predetermined, heated and placed in a cavity in a pressure transmitting medium (22, 24) which is applied to pressure over the entire surface of the medium (22, 24) to produce a predetermined densification of the material 5 (10) by means of a hydrostatic pressure exerted by the medium (22, 24), the medium being approximately dense and non-compressible and capable of flowing resiliently at least immediately prior to the predetermined densification, characterized in that the pressure transfer medium is an elastomer and contains a thermally insulating barrier means (32, 34) for surrounding the material (10) and disposing in the cavity of the elastomeric medium (22, 24) so as to produce a thermal barrier is applied between the material (10) and the elastomeric medium (22, 24) before pressure is applied to the medium (22, 24) to limit the heat transfer between the material (10) and the elastomeric medium (22, 24). .

Apparatus according to claim 13, characterized in that the thermally insulating barrier means (32, 34) comprises a first thermally insulating sheath (32) for limiting heat loss from the material (10), and a second thermally insulating sheath (34), surrounding the first sheath (32) to protect the elastomeric medium (22, 24) from heat from the first sheath (32). 25

Apparatus according to claim 14, characterized in that it contains a sealed container (12) enclosing the material (10), said first sheath (32) having an inner cavity corresponding to the outer surface of said container (12). 12) for recording it.

Apparatus according to claim 15, characterized in that the first sheath (32) is a monolithic material enclosing the container (12). 35

Apparatus according to claim 14, 15 or 16, characterized in that the second sheath (34) consists of two DK 160680 B or more parts which fit together to enclose the first sheath (32).

Apparatus according to any one of claims 13-17, characterized in that the thermal barrier means (32, 34) is at least partially fluid and capable of flowing immediately before the predetermined condensation.

Apparatus according to any one of claims 13-17, characterized in that the thermal barrier means (32, 34) contains at least partially reinforcing fibers.

Apparatus according to any one of claims 13-17, characterized in that it includes a cartridge (16) and a die (14) for applying pressure to the medium (22, 24).

Apparatus according to claim 20, characterized in that the elastomeric medium (22, 24) consists of a first (22) and a second (24) part, the first part (22) being secured in a cavity (26 ) in the die (14), and the second portion (24) is attached to the die (16), the die (16) being movable in and out of the cavity (26) in the die (14) in close sliding relationship, whereby it is the first and second elastomeric members (22, 24) and the die (16) and the die (14) are configured so that the die (16) enters the cavity (26) in the die (14) before said elastomers portions (22, 24) engage one another and enclose the thermal barrier means (32, 34) in the cavity defining the first and second elastomeric portions 30 (22, 24) so that the first and second elastomeric portions ( 22, 24) can be opened and closed successively by opening and closing the die (16) and die (14) in a press for successively producing a plurality of densified masses (10 '). 35

Apparatus according to claim 20 or 21, characterized in that at least one of the elastomeric parts (22, 24) DK 160680 B has a number of lubricating grooves (38) in the surface in contact with the die (16) or the die ( 14), to facilitate the movement of the elastomeric parts 1 relative to the respective surface of the die (16) or die (14). 5

Apparatus according to claim 20, 21 or 22, characterized in that a gasket (36) of a harder material than the elastomeric medium (22) is arranged in and below the edge of the cavity (26) in the matrix (14), when the cartridge (16) enters the die (14) and exerts pressure on the elastomeric media (22, 24), it is forced into a sealing connection with the wall of the cavity (26) in the die (14) at the location, wherein the die and the die abut against each other to prevent the elastomeric medium (22) from leaking between the die (16) and the die (14).

Apparatus according to any one of claims 20-23, characterized in that the package has a surface which forms an acute angle with the direction of movement of the cartridge (16) into the die (14) and which faces the cavity (26) in the die (14) and the gasket (36) having grooves (40) on its outer surface.

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