The overall objective is to develop novel heat sink composites and to test their performance under extreme loading conditions.
Two basic types of heat sinks will be developed:
Heat sinks based on copper matrix reinforced with ceramic and intermetallic (nano) particles or fibres for use in high temperatureapplications (up to 1000 °C), where excellent dimensional stability combined with good thermal conductivity play a primary role. The thermal conductivity should be comparable to Cu (300 W/mK) with a heat flux removal capability of up to 20 MW/m2. The CTE in plane direction at the interface should be adapted to the CTE of the protection material which is typically 4...9 x 10-6 K-1.
Heat sinks based on highly conductive phases (diamond, highly graphitised carbon fibres, carbon nanotubes with theoretical thermal conductivity 800-6000 W/mK) embedded in appropriate metallic matrix for use in applications, where extreme heat fluxes combined with tailored CTE are the main requirements. The CTE in plane direction at the interface should be adapted to the CTE of the supporting structure, typically 4...9x10-6 K-1.
Further requirements to both material groups are structural stability during thermal cycling within working temperature range
(e.g. n > 5 x 106), joinability (e.g. brazability, control of internal stress), dimensional stability, and acceptable costs.
The limitations of current materials will be overcome by knowledge-based combination of constituents, by optimum architecture of composites based on modelled performance and by tailored interfaces between constituents at nanoscopic level. The main aim will be to develop stable interfaces in the whole range of working temperatures without degradation of thermal conductivity. Industrially viable compounds will be developed in interaction with subproject 4. Radiation resistance of heat sinks will be assessed by subproject 3.
|ExtreMat is funded within the Sixth Framework
Programme of the European Community.