To increase the hydrophobicity and wear resistance of diamond-like carbon coatings by surface texturing using laser ablation process

• Regular surface patterns were prepared by laser ablation method.
• Hydrophobicity increased on the pillared diamond-like carbon (DLC) coatings.
• Contact angle increased up to 150° on the DLC coating with dual-sized structure.
• Friction and wear were found to be reduced on the dimpled DLC samples.

In this investigation, the hydrophobicity and wear behavior of diamond-like carbon (DLC) coatings were systemically altered by implementing micro-textures with laser ablation process. Surface textures were introduced to steel surfaces by laser ablation. Solid lubricant DLC was subsequently deposited on the textured surfaces by magnetron sputtering. The water contact angle was measured by using contact angle goniometer while the wear performance of the textured DLC coatings was studied by a ball-on-disk reciprocating sliding wear tester under simulated body fluid. The results showed that by introducing appropriate surface texture, the water contact angle of the DLC surface could be increased from 68° to about 130°. In addition, the DLC coatings with surface textures had an obvious improvement on wear performance in terms of friction coefficient and wear rate, as compared to DLC coatings. There are ~ 20% and ~ 60% reductions in the friction coefficient and wear rate. Meanwhile, the study of the effect of texturing on hydrophobicity and wear performance is discussed.