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Verfahren zur Herstellung gesinterter poroeser Verbundbauteile und mit dem Verfahren hergestellte Verbundbauteile

Manufacturing sintered composites with locally-varying properties, employs organic carrier coated with metallic powder and binder in solvent
 
: Quadbeck, P.; Reinfried, M.; Stephani, G.; Waag, U.

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DE 102006039586 A: 20060814
DE 102006039586 A: 20060814
C04B0038
German
Patent, Electronic Publication
Fraunhofer IFAM, Institutsteil Pulvermetallurgie und Verbundwerkstoffe Dresden ()

Abstract
(A1) Die Erfindung betrifft ein Verfahren zur Herstellung gesinterter poroeser Verbundbauteile sowie mit dem Verfahren hergestellte Verbundbauteile. Die so herstellbaren Verbundbauteile weisen bereichsweise voneinander abweichende Eigenschaften auf. Aufgabe der Erfindung ist es, poroese Verbundbauteile, die einfach und kostenguenstig durch Sinterung herstellbar sind, zur Verfuegung zu stellen, die eine erhoehe mechanische Festigkeit, Temperaturbestaendigkeit und lokal differenziert physikalische Eigenschaften aufweisen, zur Verfuegung stellen zu koennen. Erfindungsgemaess wird dabei so vorgegangen, dass poroese Strukturelemente als Gruenkoerper, die mit einer Suspension eines Binders und Metallpulver auf Traegern beschichtet und getrocknet sind, an miteinander zu verbindenden Oberflaechen mit einer Fluessigkeit, z. B. Wasser oder ein Loesungsmittel (waessrige Loesung), angefeuchtet, die angefeuchteten Oberflaechen der Strukturelemente in beruehrenden Kontakt gebracht und dabei mit einer Druckkraft beaufschlagt aneinander gepresst werden. Bei einer Waermebehandlung werden Kohlenwasserstoffverbindungen ausgetrieben und eine stoffschluessige Verbindung und die tragende Struktur durch Sinterung ausgebildet.

 

DE 102006039586 A1 UPAB: 20080425 NOVELTY - Two porous structural components form the green body. They will be materially-bonded together by sintering, so connecting them. Each is formed by an organic carrier surface-coated with a binder and metallic powder. The surfaces to be connected are moistened locally or over the entire area, using a solvent. They are brought into contact under applied pressure. Heat treatment drives off the hydrocarbon compounds and completes bonding by sintering, joining the components and forming a supportive structure DETAILED DESCRIPTION - The solvent is water and/or an organic liquid. The metallic powder is in suspended form, in a solvent. Pressure forces are applied using an elastic organic carrier material of at least one structural component. The structural components connected, have open- and closed-pore structures. At least one structural component in the form of an elastic, deformable carrier, is caused to match the surface configuration of the other structural component during formation of the materially-bonded connection between the structural components. A structural component formed by organic, thread-like connected elements is used for bonding. Structural components made from differing metals are bonded. The joint region forms an alloy, intermetallic phase and/or mixed crystals. Locally, porosity and/or pore size differ. Locally the structure has open- or closed cells. These properties may have gradient-variation. There are one or more materially-bonded hollow spheres formed by sintering. A metal foam region is included. AN INDEPENDENT CLAIM IS INCLUDED FOR the composite so formed. USE - To manufacture porous sintered composites with locally-varying properties. ADVANTAGE - The range of uses of sintered components is extended. manufacture is flexible, to suit the particular application. The actual process is comparatively simple. It may be used to make small numbers of components, or for prototyping. It lends itself to production of light constructions which are sound- and heat insulating. Bonding is secure, exceeding the strength of glued composites. Practical examples clarify the process. A carrier comprises e.g. polystyrene spheres. They are coated with a mixture of stainless steel particles suspended in water and polyvinyl alcohol, as binder. This forms the first green structural component. A second carrier of a different plastic may be used with a coating to form a differing structural component. Sintering follows. Process conditions and a further example are elaborated.

: http://publica.fraunhofer.de/documents/N-75273.html