For the coating of divertor wings, which in an adapted form may also be suitable for divertor targets, tungsten coatings were developed and optimized with respect to erosion and adhesion behaviour and tested in the Jülich JUDITH facility as well as in the St. Petersburg TSEFEY facility. For the improvement of adhesion, interlayers were developed and used for the coating of mock-ups. In order to achieve a further improvement in adhesion and thus better heat removal, structures were developed for the substrate surfaces. Substrate materials are copper according to DIN 1787 and the Elmedur X copper-chromium-zircon alloy. Differently produced tungsten coatings on mock-up substrates were loaded until failure by means of an electron beam. The area-related thermal loads introduced until failure were measured and correlated with the production parameters.

With a view to the development of thermal barrier coatings on turbine blades, such coatings were developed on the basis of Y2O3-stabilized ZrO2 and optimized with respect to their reproducibility. Particular attention was given to the spray efficiency and, in particular, the coating porosity. The porosity was measured by Hg porosimetry, which proved to be a reliable method of characterization. The plasma gas flows play an important role for a high reproducibility of the coating properties. High reproducibility of the porosity and spray efficiency was achieved for low argon flows, for which the influences of all the other parameters, such as electric arc current, meandering and sample cooling during plasma spraying or the cathode operating time of the burner, were of minor relevance for the coating properties. The spray efficiency is clearly influenced by the given powder rate and the carrier gas flow for the type of burner used. The change of the grain fraction in the plasma jet was examined for two different powders. Finally, thermal cycling tests were carried out and evaluated for pre-optimized thermal barrier coating samples.

The new Triplex-burner was used to develop 7 wt% Y 2 O 3 stabilised ZrO 2 thermal barrier coatings and to optimise the process parameters with respect to reproducibility. The investigations were focused on spray efficiency and coating porosity. Porosity levels and porosity distribution were measured with mercury intrusion, which turned out to be a very reliable characterisation technique. High reproducibility could be achieved in particular for low argon fluxes: the deviation of the porosity levels was below about 4%. Paper text in German.

Tungsten coatings on copper substrates were produced and subjected to thermal shock loads in an electron beam device. The aim was to minimize the erosion rates thus caused. They are basically dependent on the level and type of porosity. Moreover, material erosion can also be directly influenced by the spraying parameters in coatings with the same relative density. In this connection, the chamber pressure, powder size and spraying distance play a decisive role.

High-Z materials such as tungsten are currently considered more suitable for the inner coatings of fusion devices than low-Z materials. The VPS parameters are being optimized for different tungsten powders with respect to uniform pore distribution and distribution of unmelted particles in the coating. High process reliability is aimed at in coating production. Copper is used as the substrate material. The spray efficiencies, coating porosities and unmelted particles in the coatings are being examined and the microstructures evaluated. Spraying parameters are determined for two different powder fractions leading to relative densities ≥ 90 % of the theoretical density.

For simulating residual stresses in plasma sprayed multilayer systems a finite element and an analytic model are compared with measured results. The measured stresses which depend on substrate temperature of the plasma spray process are produced exactly by the finite element model. Mesh deformation and simulated stress distribution of the sample are studied.