Tribological and adhesive properties of the tungsten-doped diamond-like carbon film prepared by double lasers deposition

The nanosecond and femtosecond lasers were used to ablate the graphite and tungsten targets simultaneously, and the tungsten-doped DLC film with the different tungsten concentration on the strip substrate was prepared. The content of the tungsten in the doped DLC film varied continuously in the horizontal direction and was changeless in the vertical direction. The tungsten content in the doped DLC film increased gradually when it was close to the center axis of the tungsten plasma generated by femtosecond laser. Surface roughness and the critical load of the tungsten-doped DLC film increased with the increasing of tungsten content. On the other hand, the friction coefficient of the tungsten-doped DLC film decreased firstly and then increased when the tungsten content increased gradually. The minimal friction coefficient was 0.086 when the tungsten content was about 8.07 at.%. The deposition method designed in this experiment also could be used for other doped films in the field of the function films.