Forschungszentrum Juelich Gmbh

Mtu Aero Engines Gmbh

Forschungszentrum Julich Gmbh

Detlev Stoever

Robert Vassen

Hans-Peter Buchkremer

Hans Peter Buchkremer

Frank Tietz

Martin Bram

Uwe Schulz

Wilhelm Albert Meulenberg

Bilge Saruhan-Brings

Daniel Emil Mack

Jose Manuel Serra Alfaro

Stefan Baumann

Christian Friedrich

Wolfgang Wachter

Gerhard Pracht

Wolfgang Jungen

Qingxi Fu

Sonja-Michaela Gross

Sigrid Schwartz-Lueckge

Berthold Coenen

Claus-Juergen Kroeder

Manuel Koehl

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

The invention relates to an anode for a high-temperature fuel cell having an anode substrate and/or a functional anode layer, comprising a porous ceramic structure having a first predominantly electron-conducting phase with the general empirical formula SrLnTiOwherein Ln=Y, Gd to Lu and 0.03&#x3c;x&#x3c;0.2, and having a second predominantly ion-conducting phase component comprising yttrium or scandium-stabilized zirconium dioxide (YSZ or ScSZ). In the anode substrate and/or the functional anode layer, the ratio by volume of the first phase to the second phase ranges from 80:20 to 50:50, and particularly from 70:30 to 60:40. The porosity of the entire anode ranges between 15 and 50% by volume. The anode additionally comprises a catalyst in the amount of no more than 15% of the total volume, which is disposed on the surface of the pores of the ceramic structure.

Ceramic material combination for an anode of a high-temperature fuel cell

A composite membrane for selective gas separation, comprises a layer system having a continuously porous, mechanically stable carrier layer, which has an average pore size in the &#x3bc;m range, further having at least one continuously porous intermediate layer, which is disposed on the carrier layer and has an average pore size in the range of 2 to 200 nm, and further having a gastight functional layer, which is disposed on the intermediate layer and is made of a mixed-conductive material having a maximum layer thickness of 1 &#x3bc;m. The carrier layer comprises a structural ceramic, a metal, or a cermet and has a layer thickness of no more than 1 mm. The intermediate layer is present with a total layer thickness of no more than 100 &#x3bc;m and has an average pore size in the range of 10 to 100 nm. The functional layer comprises a perovskite, a fluorite, or a material having a KNiFstructure, such as LaSrCoFeO(LSCF). The layer thickness of the functional layer is no more than 50 nm, and particularly between 25 and 400 nm. In order to produce this composite membrane, at least one porous intermediate layer is applied onto a continuously porous, mechanically stable carrier layer, which has an average pore size in the &#x3bc;m range, wherein the intermediate layer has an average pore size in the range of 2 to 200 nm. A further gastight, functional layer made of a mixed-conductive material and having a maximum layer thickness of 1 &#x3bc;m is applied onto the intermediate layer.

Oxygen-permeable membrane and method for the production thereof

A method produces thermal barrier coatings that adhere to components even at high temperatures and temperatures that change frequently. A gas-tight glass-metal composite coating is applied to the component and annealed. The corroded part of the gas-tight coating is then removed, and a second, porous coating is applied. The second coating can comprise a ceramic, in particular yttrium-stabilized zirconium oxide. A thermal barrier coating is provided that is a composite made of a gas-tight glass-metal composite coating and another porous coating disposed thereover. Because the boundary volume of the composite coating is partly crystallized to the other coating, superior adhesion within the composite is achieved. Thus, it is in particular possible to produce a composite made of silicate glass-metal composite coatings and yttrium-stabilized zirconium oxide that are temperature-stable for extended periods of time. Such a composite is particularly advantageous for use as a thermal barrier coating because it combines good protection against oxidation with low heat conductivity and susceptibility to aging.

Sandwich thermal insulation layer system and method for production

A heat-insulating layer has a melting point above 2500&#xb0; C., a thermal expansion coefficient in excess of 8&#xd7;10K, and a sintering temperature greater than 1400&#xb0; C. This material has a perovskite structure of the general formula A(B'B&#x2033;)Oin which:

Heat-insulating layer made of complex perovskite

A heat-insulating layer system for a metallic structural component, especially for a structural component of a gas turbine such as an aircraft engine, includes an adhesion promoting layer (), an inner contact layer (), and an outer cover layer () , whereby the adhesion promoting layer (). is disposed on a surface () of the gas turbine structural component (). The inner contact layer () is formed of a zirconium oxide partially stabilized with yttrium or yttrium oxide, and the outer cover layer () is formed of a material that consists of at least one component with at least one phase, which stoichiometrically comprises 1 to 80 Mol-% MxO, 0.5 to 80 Mol-% MyO and AlOas a remainder with incidental impurities, wherein Mx is selected from the elements chromium and barium or mixtures thereof, and wherein My is selected from the alkaline earth metals, the transition metals and the rare earths or mixtures thereof.

Heat-insulating layer system

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Niederzier, Germany

Detlev Stoever