The Tribological Behavior of the DLC-Coated Engine Surfaces Lubricated with Oils with Nanoadditives

Nowadays, it is commonly strived to achieve the highest efficiency of internal combustion engines and the longest possible inter-repair millage conditioned by low wear of engine components. This needs the reduction of the friction and wear intensity for the mating surfaces of engine components. This is commonly achieved by using the right oil, its additives and coating the surface with protective layers. Various nanoparticles, such as TiO₂, ZrO₂, CuO can be added to the base oil to change lubricating properties and creating so-called nano-oils. Parallelly, mating engine surfaces are often covered with very thin DLC coatings. Lubrication of DLC-coated surfaces with nano-oil can create both positive and negative synergy effects. The goal of the present review is to recognize the state-of-art in terms of existing types of DLC coatings and techniques for their application, types of nanoparticles dispersible in engine oils and the tendency to create a synergistic effect in contact zones.