Diamantartige Kohlenstoffschichten steigern die Effizienz

Rising prices for fossil fuels as well as the increasing effects of the climate change due to the emission of greenhouse gases reveal the necessity of saving energy. Low friction coatings have an enormous potential in saving energy. Carbon based coatings - named as DLC coatings - are especially well suited for low friction coatings. In particular hydrogen-free tetrahedral amorphous carbon (ta-C) coatings are of great interest due to their extraordinary low wear properties. In addition they show excellent low friction properties and especially in combination with specific lubricants the so-called super low friction effect. For the deposition of ta-C coatings PVD methods have to be applied instead of CVD methods as it is the case for conventional DLC coatings. We have developed a deposition method which is based on a pulsed arc steered by a laser (Laser-Arc). This allows us to use large cathodes resulting in a high long-term stability. Furthermore, the carbon plasma source can be combined with a filtering unit removing almost all droplets and particles, which usually are characteristic for an arc process. The resultingLaser-Arc source allows for the deposition of smooth and virtually defect-free ta-C coatings with a competitive deposition rate.