Advanced Ceramic Tribological Layers by Thermal Spray Routes

Protective and functional coatings featuring outstanding tribological performance are of general interest for all kinds of industrial applications i.e for high performance automotive and mechanical applications. Thermal spray coating technologies play a key role in fabricating hard layers based on ceramic, metal - ceramic and further multiphase materials. Additional functionality can be achieved by combining these coatings with polymer based top coats with low friction coefficient or anti adhesive behaviour. Combined coatings feature also designed thermophysical and electrophysical properties. Several case studies will be discussed, ranging from automotive applications to paper and printing industry. Thermally sprayed coatings were applied using APS, HVOF and the newly developed HVSFS processes (High Velocity Suspension Spraying) with a special focus on nanoceramic feedstocks. In some applications polymer top coats with dispersed solid phases are applied to enhance functional properties. Special aspects in manufacturing engineering are addressed with particular importance not only of the influence of spray process parameters on coating properties but also of spray torch kinematic and robot trajectories on hardness, residual stress distributions, dimensional tolerances and porosity distributions will be discussed.