The role of wetting and adsorption in lubricated green DLC contacts

摘要

DLC coatings continue to grow their use and importance in many industrial applications. From their early anti-sticking and low friction role in dry conditions, their role and benefits in lubricated contacts are more and more important. A special issue became the low SAPS additives and other green lubrication concepts due to environmental effects and legislation behind this. A combination of DLC with inherently low wear and low friction behavior offers a potential to use milder and greener additives. However, adsorption of any additive, even mild, must be well controlled and understood, which is still not resolved completely. Moreover, in recent studies it was revealed that DLC coatings offers also a low friction in EHD lubrication. The low friction was strongly correlated with surface energy of DLC and their wetting behavior, which also have an influence on adsorption of oils and additives. These phenomena and some early results from various experimental methods and techniques are discussed in this work.