PVD coatings to optimize frictional power transmission

PVD coatings to optimize frictional power transmission

SEM – image of a coating with high static friction
© Fraunhofer IWS
SEM – image of a coating with high static friction

Frictionally engaged component connections such as clamp, flange or screw connections are present in nearly all technical applications including mobile powertrains, steel constructions and wind energy systems. Such connections can transmit more power and higher torques if the static friction between the connecting surfaces is increased or if more connection elements (e.g. screws) are installed. Alternatively, higher static friction would be beneficial to maintain power transmission with reduced dimensions of connection elements and thus improved volume efficiencies.

By means of a suitable coating design, IWS engineers were able to use the droplet-induced roughness of the a special coating design to create surfaces with very high static friction. Combined with the high wear resistance and good adhesion to the substrate this system offers an excellent solution to create reliable and long-term stable static friction performance for a given friction couple. The coating is produced by vacuum arc deposition and has a thickness of around 3 microns. So the coating does not influence geometrical tolerances of mechanical components.