Forschungszentrum Julich Gmbh

Siemens Aktiengesellschaft

Forschungszentrum J&uuml;lich Gmbh

Willem J Quadakkers

Werner Stamm

Hubertus Nickel

Frank Tietz

Daniel Emil Mack

Vladimir Shemet

Lorenz Singheiser

Norbert H Menzler

Mohsine Zahid

Andreas Hospach

Alexander Gil

Ferdinand Baumanns

Robert VAßEN

Jan Bergholz

Joanna Zurek

Philip James Ennis

Alloys containing aluminium are characterised by an outstanding oxidation resistance at high temperatures, that is based on, inter alia, the formation of a thick and slow-growing aluminium oxide layer on material surfaces. If the formation of the aluminium oxide layer reduces the aluminium content of the alloy so far that a critical aluminium concentration is not reached, no other protective aluminium oxide layer can be formed. This leads disadvantageously to a very rapid breakaway oxidation, and the destruction of the component. This effect is stronger at temperatures above 800&#xb0; C. due to the fact that, often at this point, metastable AlOmodifications, especially &#x3b8;- or &#x3b3;-AlO, are formed instead of &#x3b1;-AlOthat is generally formed at high temperatures. The above-mentioned oxide modifications are disadvantageously characterised by significantly higher growth rates. The invention relates to methods whereby aluminium-containing alloys advantageously form an oxidic covering layer predominantly consisting of &#x3b1;-AlO, at a temperature higher than 800&#xb0; C., especially in the initial stage of oxidation, and thus have a significantly improved long-term behaviour.

Protective layer for an aluminum-containing alloy for high-temperature use

The invention relates to a component having a substrate and a protective layer, which consists of an intermediate NiCoCrAlY layer zone on or near the substrate and an outer layer zone which is arranged on the intermediate NiCoCrAlY layer zone, which is characterized in that the intermediate NiCoCrAlY layer zone comprises of (in wt %): 24-26% Co, 16-18% Cr, 9.5-11% Al, 0.3-0.5 Y, 1-1.8% Re and Ni balance.

Component with a protective layer

A method is disclosed for producing a protective coating on a chromium oxide-forming substrate, which comprises the steps of:

Protective coating for substrates that are subjected to high temperatures and method for producing said coating

An oxidation resistant component is disclosed comprising a substrate and a protective layer. The protective layer consists of an inner MCrAlY layer contiguous with the substrate and an outer layer consisting of at least Ni and Al and having a &#x3b2;-NiAl structure

Highly oxidation resistant component

MCrAl layers according to prior art often display chipping of the thermally grown aluminum oxide layer (TGO) as a result of thermally induced stresses, which significantly reduces the oxidation behavior or the bonding behavior of ceramic heat insulating layers. An inventive MCrAl layer is designed in such a way that the TGO created thereon is microporous and thus allows expansion. The microporosity of the TGO is ensured by adding elements into the MCrAl layer in a targeted manner.

MCrAl layer

In a method of producing on the surface of a component which consists of a titanium alloy or an intermetallic phase on the basis of titanium, a protective layer (according to the formula Ti Ag Al , O ), a mixture of Ti powder and TiO powder, which has been sintered, is applied to the surfaces of the component or, if the titanium alloy includes 40-60 at % Al, a coating of silver is applied to the component and the component is then heat treated at 500 to 900&deg; C. to form the protective layer on its surfaces.

Component covered with a layer and method of producing such a layer

Metallic bipolar plate for high-temperature fuel cells and method of

Components based on intermetallic phases of the system titanium-aluminum

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Wijnandsrade, Netherlands

Willem J Quadakkers