P. Worbs (Sp), Max Planck Institute for Plasma Physics, Garching (Germany); B. Schwarz, Vienna
University of Technology (Austria); H. Maier, H. Bolt, Max Planck Institute for Plasma Physics,
Garching (Germany)
The divertor design of the ITER fusion machine comprises joints between carbon fibre reinforced carbon (CFC)
composites and the copper alloy heat sink. The main problem of the CFC-Cu joint manufacturing is the large
thermal expansion mismatch of the components and the very high contact angle of molten copper on carbon
substrates. The aim of this work is to improve the wetting behaviour in the C/Cu system. In order to achieve this,
thin TiC interlayers with variations in stoichiometry have been produced by dual magnetron sputter deposition on
graphite substrates. For optimization of the deposition parameters an intrinsic stress evaluation of the TiC films
has been carried out. The wetting behaviour of Cu and a Cu-Ti alloy on TiC with a range of stoichiometry has been
characterized using the sessile drop method. Both, increasing the Ti-concentration in the TiC layer and alloying
the liquid copper with 2.78 atomic percent titanium improves wetting dramatically. Morphological and mechanical
analyses have been performed to characterize the samples.