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Projekt Druckansicht

Entwicklung von Werkstoffsystemen mit eingestellter anisotroper Wärmeleitung für Maschinenkonstruktionen

Fachliche Zuordnung Ur- und Umformtechnik, Additive Fertigungsverfahren
Förderung Förderung von 2011 bis 2016
Projektkennung Deutsche Forschungsgemeinschaft (DFG) - Projektnummer 211075466
 
Erstellungsjahr 2015

Zusammenfassung der Projektergebnisse

The project was executed with success. The capability of metal/polymer laminate sheets and thin thermally sprayed metal/ceramic multi-layered coatings to anisotropically conduct locally brought-in surface heat was proved. Produced samples were investigated, calculated and improved according calculation to maximize anisotropic heat conductive effects. Investigations were focused on internal interfaces of the laminated and multi-layered structures. Cut-bar method was applied for heat transfer investigation across the prepared samples. Metal/ceramic multilayer system presented that increasing the number of layers and especially topmost layer thicknesses increase the insulation effect in the depth. A 1 mm thick seven-layered coating system effects a temperature drop from 100 °C to 25 °C within a coating volume of 1 mm³. For high accuracy tool machine parts, the multi-layered metal/ceramic coating systems are a promising solution. The ceramic layers provide an effective insulation from local heat sources in rectangular direction to a component’s surface, while the metallic layer evenly distributes locally introduced heat. An increased number of layers and thickness of topmost layers effectively increase the insulation effect of the whole layer system. Hence, according calculation it is possible to decrease the temperature load of a local heat source within an 1 mm³ coating volume from 100 °C to about 25 °C on the components surface by applying a multi-layered metal/ceramic coating system of about 1 mm thickness. By use of the APS process, such calculated coating systems can be produced reproducibly. The single coating layers demonstrate a close material contact to the substrate and to each other in cross section investigations, representing high mechanical interlocking that stands for good coating/layer adhesion. Cracks are scarcely detectible, what hints on low thermally induced stress levels. The porosity in both metal and ceramic layer type ranges in a level known from the state of the art of plasma sprayed coatings. In comparison to the calculated results, pores present in the ceramic layers will increase the thermal depth insulation effect. Also, CAPAAL and CAPAT samples were identified to represent candidates for the desired material behaviour of highly anisotropic heat conductivity. Thermal stress induced defects within the metal/plastic interfaces could be minimised by mechanical pre-treatment (defined grit blasting) of the metal component surface and were further reduced by application of glass fibre reinforcement instead of carbon fibres. Both approaches - metal/ceramic multilayer coatings and metal/plastic hybrid laminates - succeeded in the anisotropic transfer of locally introduced heat on sample surfaces. In both cases, heat conduction parallel to the samples surface took place via the metallic system component, whereas heat insulation rectangular to the samples surface was gained by multiple system inherent interfaces as well as the applied - and in comparison to metals - heat insulating ceramics and plastic layers.

Projektbezogene Publikationen (Auswahl)

 
 

Zusatzinformationen

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