Effects of Al incorporation on the mechanical and tribological properties of Ti-doped a-C:H films deposited by magnetron sputtering

► Ti-doped and TiAl-doped a-C:H films were deposited by magnetron sputtering technique. ► Al doping made the surface smoothen, lowered the residual stress and improved the film toughing. ► TiAl-doped a-C:H films possessed lower wear rate and friction coefficient.