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Beschichtung zur Verminderung der Erosion an thermisch hochbelasteten Oberflaechen aus faserverstaerkter Keramik und Verfahren zu deren Herstellung

Coating reducing erosion of fiber-reinforced ceramic surfaces under high thermal loading, contains nitride, oxonitride or oxide of chemical elements contained in ceramic.
 
: Hirsch, K.; Kaiser, M.; Greiner, A.; Bill, J.; Aldinger, F.

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Frontpage ()

DE 1999-19928173 A: 19990619
DE 1999-19928173 A: 19990619
WO 2000-EP5555 A: 20000616
DE 19928173 A1: 20001221
C04B0041
C04B0041
Deutsch
Patent, Elektronische Publikation
Fraunhofer ICT ()

Abstract
Es wird eine Beschichtung zur Verminderung der Erosion an thermisch und/oder oxidativ hochbelasteten Oberflaechen aus faserverstaerkter Keramik, insbesondere Hitzeschilden an Flugkoerpern, Brand- und Katastrophenschutzeinrichtungen o. dgl., vorgeschlagen. Die Beschichtung besteht aus Nitriden und/oder Oxonitriden (-N=O) und/oder Oxiden von wenigstens einem in der Keramik enthaltenen chemischen Element, insbesondere Silicium. Durch eine solche Beschichtung wird insbesondere die Erosion eines Hitzeschildes zu Beginn einer thermisch oxidativen Beanspruchung, wie sie beispielsweise beim Eintritt eines Raumflugkoerpers in die Erdatmosphaere auftritt, erheblich vermindert. Ferner werden Verfahren zur Herstellung einer solchen Beschichtung vorgeschlagen.

 

DE 19928173 A UPAB: 20010302 NOVELTY - The coating contains nitride(s) and/or oxonitride(s) (-N=O) and/or oxide(s) of at least one of the chemical elements contained in the ceramic. DETAILED DESCRIPTION - An INDEPENDENT CLAIM is included for the method of making the coating using physical vapor deposition (PVD). Preferred features: Layer thickness is 1-500 mu m. It is 10-50 mu m. The coating is applied by one of the following alternatives: chemical vapor deposition (CVD); plasma spraying; plasma polymerization followed by thermal treatment; or infiltration of a polymer or polymer solution into the surface to be protected, followed by thermal treatment. Thermal treatment takes place at a temperature between 500 deg. C and 1500 deg. C. It takes place under reduced pressure and/or inert gas atmosphere. USE - To protect surfaces of e.g. heat shields for flying bodies (particularly fast ones). To construct fire- and emergency protection systems, which are subject to high thermal loading. ADVANTAGE - The coating reduces erosion under thermal and/or oxidizing conditions. Oxidation and sublimation are resisted. Higher thermal resistance is achieved. Contact of material below the protective surface, with molecular- and atomic- oxygen or nitrogen, is prevented. Inhibition of oxidation, also assures that no additional heat will be liberated to accelerate deterioration; especially important where carbon is present. Carbon typically forms the reinforcing fibers, and may result from any organic polymers present. Reaction, reaction kinetics, manufacture, reaction products and specific materials are discussed in further detail in the disclosure.

: http://publica.fraunhofer.de/dokumente/N-44393.html