PVD Coating - Applications in fluid engineering

Hydrostatic pumps and engines are essential components of hydraulic mechanisms. They transform mechanical energy into hydraulic energy and vice versa. Hydrostatic machines and their standard fluids based on mineral oils have been developed to high technical standard. The fluids in this case are biologically harmfull and often toxic. Fluids that are environment friendly must not include additives that are toxic. Due to the lack of additives, many environment friendly fluids have worse tribological properties than standard fluids. If these liquids should be used, important tribological qualities of the fluid must be transmitted to the materials. This can be achieved by redisegned coatings. In order to gain basic information about the quality of the coatings, experiments have to be performed using a tribometer. Coatings that are graduated like 'HfCg' show a low friction coefficient and wear rate.