Evaluation of the surface properties of PEEK substrate after two-step plasma modification: Etching and deposition of DLC coatings

• Physicochemical and mechanical properties of modified PEEK substrate are presented.
• The properties of manufactured DLC depend on the applied etching process.
• Etching of PEEK using methane plasma increases its mechanical properties.

This paper presents results of research on the change of the surface properties of poly (ether–ether–ketone) PEEK substrates under the influence of two-stage processes of the coatings production. Those modification processes included the etching procedure in oxygen, nitrogen and methane atmosphere, as well as synthesis of carbon coatings in methane plasma. After both the etching process and the synthesis of diamond like carbon DLC coating, the modified samples were analysed in terms of the changes in surface geometry, its chemical composition, nano-scale mechanical properties, the contact angle and the surface free energy, as well. The work also includes a comparison of changes in the friction coefficient for each set of process parameters applied in the synthesis of carbon coatings.