From DLC to Si-DLC based layer systems with optimized properties for tribological applications

► DLC and Si-DLC with low hydrogen contents of 10 at.% and 6 at.% were deposited. ► A clear influence of hydrogen on mechanical properties of DLC coatings is shown. ► Si-DLC/DLC films of 30 GPa hardness and friction coefficient of 0.07 were achieved. ► Thermal stability up to 500 °C was achieved by adding Si to DLC coatings.