Thermally active materials like zeolites, metal-organic frameworks or phase-changing materials are used in different systems for energy storage and energy transformation, e.g. refrigeration machines or heat pumps. Most of the active materials exhibit a very low thermal conductivity and strength and depend on heat-conducting support structures. Such structures, like lamella heat exchangers or foams, are mostly made from metals. Typically, the metal support is produced first and combined with the active material afterwards, e.g. by filling with material (pellets/granules), slurry coating or in-situ crystallization. In the presented work a different approach is chosen: the integration of the active material directly during the production of the support metal structure or even of the full heat exchanger.
Different approaches for the direct integration of active material into metal support structures can be followed. We present an example where granules of Y-zeolite are embedded into the surface of preforms made from polymer lattices. Then the preforms are infiltrated with aluminium melt by means of squeeze-casting. Subsequent decomposing of the polymer results in open porous aluminium sponges with embedded zeolite granules. This approach allows also the direct integration of fluid system elements like tubes. In the presentation details of the process and the resulting structures will be shown. Furthermore, the response of the zeolite material to the thermal and mechanical loads during the production process and the thermal performance of the zeolite-aluminium composite were investigated. The presentation will conclude with a comparison to conventional approaches and an evaluation of the market potential of the newly developed composites.