Turbine blades in hydropower plants have to withstand the most severe seasonal loading conditions when the river water is heavily loaded with sediments. Welded blade surfaces are considered state of the art, but they cannot withstand the aggressive, eroding and abrasive loading conditions in the major rivers in China. Once a year there is flooding with a maximum amount of sediment in the river water. This is why coating systems with maximum wear resistance must be developed, examined, produced and tested over a maximum period of time. In this article, the wear results of various coating systems examined in a special test facility are described in order to obtain comparable results from several proposed coating systems together with material classification tests. Paper includes a German-language abstract.

Thermal spraying offers the possibility of applying functional metal, ceramic or cermet coatings to components with different geometries and materials and significantly improving their thermal, mechanical, and chemical properties. The performance in operation as well as failure due to deformation, cracks, and delamination are mostly determined by the internal stress state within the coated components. This paper reviews coating developments on light metal and glass substrates, sprayed with different atmospheric plasma spray process spray parameters are reviewed. The results show that from the numerical and experimental residual stress analysis, the injection parameters can be influenced individually. This leads to optimized residual stress states in the coated components with regard to the expected operating loads. Paper includes a German-language abstract.