Forschungszentrum Juelich Gmbh

Forschungszentrum Julich Gmbh

Martin Bram

Hans Peter Buchkremer

Detlev Stöver

Robert Vassen

Willem J Quadakkers

Olivier Guillon

Detlev Stoever

Wilhelm Albert Meulenberg

Helmut Ringel

Ernst Riensche

Reinhard Menzer

Jesus Gonzalez

Norbert H Menzler

Leszek Niewolak

Jewgeni Nazarko

Li Zhao

Marc Rubat Du Merac

Diana Marcano

Joanna Zurek

Heinz Nelles

Stephan Reckers

Rolf Steinbrech

Alexander Laptev

Manuel Koehl

Andreas Hospach

Berthold Coenen

Detlev Stover

Ludger Blum

A method for producing a transparent polycrystalline ceramic includes forming at least one planar transparent region near a surface within the ceramic, wherein the at least one planar transparent region has a lower thermal expansion coefficient than other regions of the ceramic. The method further includes generating compressive stresses in the at least one planar transparent region near the surface after a thermal treatment and cooling.

Method for reinforcing transparent ceramics, and ceramic

Disclosed is a method for producing a metal or ceramic component having regions of differing porosities. The method includes subjecting powder or a presintered precursor to a pressure-assisted pressing and sintering step, using at least one punch for the pressing step. The at least one punch has a contact surface that is intended for making contact with the powder or the presintered precursor and that has a flat outer region and an inner region having a concave recess. After the sintering step, a component is obtained that has a flat outer compacted region having a first porosity and an inner porous region having a second porosity. The component has, on at least one side, a defined transition region between the outer region and the inner region.

Method for producing metal or ceramic components and components

Storage material, for storing electrical energy by reduction or oxidation of an active component, comprises the active component in at least a reduced and/or oxidized form and a reactive framework structure that is capable of chemically integrating at least one form of the active component in the form of a mixed oxide or an alloy into the reactive framework structure during the charging or discharging process. In the case of an oxidic framework structure, said integration can occur by formation of at least one stable mixed oxide of the active component and an oxide from the framework structure. In the case of the metallic framework structure, said integration can occur by forming an alloy of active component and at least one metal of the framework structure.

Electrochemical storage material and electrochemical storage device for storing electrical energy, comprising such a storage material

Disclosed is a method for producing semi-finished products from a shape memory alloy, particularly an NiTi shape memory alloy, wherein a powder is first produced from a shape memory alloy, and subsequently the powder is divided into a coarse fraction and a fine fraction in a separating cut T. While the fine fraction is required, in particular, for the production of a first semi-finished product, employing the metal injection molding (MIM) method, the coarse fraction can be used for the production of a second semi-finished product, employing the hot isostatic pressing (HIP) method. The advantages of the invention can be summarized as follows. The MIM method for producing semi-finished products from a shape memory alloy is qualitatively improved and more cost-effective to implement if the coarse fraction that is typically obtained during powder production, but not used for the MIM process, can advantageously be supplied to a further process, in this case the HIP process. Due to the use of particularly fine powder, the semi-finished products produced by way of the MIM method have an advantageous, powder-metallurgical microstructure. In particular, the alloying elements are distributed particularly homogeneously in these semi-finished products, casting flaws or segregations do not usually occur, no anisotropy of the structure occurs as a result of the processing steps, and ternary alloys can be processed, which due to the mechanical properties thereof, cannot be processed by way of conventional forming methods.

Method for producing semi-finished products from NiTi shape memory alloys

Carbon dioxide is separated from a flue gas produced in a combustion plant. Flue gas is supplied to a membrane unit having at least one membrane module provided with a membrane that is selective for CO. A portion of the COis separated from the flue gas in the module, producing a CO-enriched permeate. CO-depleted flue gas remaining on the retentate side of the module is supplied to at least one additional COseparating unit and a portion of the COin the retentate is separated by an absorbent. The result is a reduction in energy consumption.

[object Object]

A porous near-net-shape metallic parts with an open porosity of at least 10% by volume is made by first forming an injectable mass of a metallic powder of stainless steel, Ti, NiTi, or a titanium alloy, at least one thermoplastic binder, and at least one place holder. The mass then injection molded into the shape of the part to be produced, cooled, set in a capillary-active material, and subjected to a first-stage binder removal to produce an open porosity. The place holder is then removed at least partially from the part with a fluid, and the part is subjected to a thermal binder-removing process. Finally the part is sintered.

Method for the production of near net-shaped metallic and/or ceramic parts

The invention relates to a high-temperature resistant seal, particularly a seal for use in a high-temperature fuel cell. The inventive seal comprises a structured metallic layer having at least one area on whose surface a filler is placed. The filler is comprised, in particular, of clay minerals or ceramic materials. The seal thus advantageously combines the sealing properties of a metallic layer, for example, of an undulated metal foil with the elastic properties of the filler. The seal is particularly suited for use at high temperatures and thus, for example, in high-temperature fuel cells.

High-temperature resistant seal

The invention relates to a method for producing highly porous, metallic molded bodies. The inventive method consists of the following steps: a metallic powder used as a starting material is mixed with a dummy; a green body is pressed out of the mixture; the green body is subjected to conventional mechanical machining, the dummy advantageously increasing the stability of the green body; the dummy material is thermally separated from the green body by means of air, a vacuum or an inert gas; and the green body is sintered to form the molded body and is then advantageously finished. Suitable materials for the dummy are, for example, ammonium bicarbonate or carbamide. The mechanical machining carried out before the sintering advantageously enables a simple production close to the desired final contours, even for complicated geometries of the molded body to be produced, without impairing the porosity, and without high wear of the tools. The workpiece is advantageously sufficiently stable in terms of pressure for the green machining as the dummy material is still present in the pores of the green body during the machining.

Method for producing highly porous metallic moulded bodies close to the desired final contours

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Juelich, Germany

Martin Bram