Yttrium containing aluminide layers

The development of efficient gas turbines leads to an increasing of the combustion temperature. Therefore the improvement of the protective coatings for the turbine components is an important factor. These high temperature protective coatings enhance the oxidation and corrosion resistance of the nickel base material components. Different coating processes were developed and since several years NiAl and modified NiAl layers were used for this application. Based on an AlCl 3 /Al/YCl 3 chemical vapour deposition process (CVD process) aluminum and yttrium containing aluminum coatings were investigated. The evaporation and codeposition processes were studied and GTD111 samples with different geometries were coated with aluminum and yttrium/aluminum. The composition of the coatings were determined and the measured yttrium amount of the layer was correlated with the deposition conditions. The prepared samples were tested in a thermal cycling oxidation test and the enhanced oxidation resistance of the yttrium containing coatings were shown.