Effect of individual and multiple incorporation of Ag and TiO2 on the properties of DLC films

DLC films have properties that make them known as solid lubricants and can be improved by incorporating nanoparticles. This work evaluated the influence of individual and multiple Ag and TiO2 incorporation on DLC films, with the main objective of its application in high vacuum. Nanoparticle suspensions prepared from Ag and TiO2 precursor powders in deionized water were incorporated into the DLC films using a pulsed valve coupled to a modified pulsed-DC PECVD system deposition. Raman analysis showed a low graphitic behavior for all samples deposited. The friction coefficient for high vacuum conditions showed that nanoparticles promoted the stabilization of this trybo-parameter compared to the coatings without modification and reduced the running-in period. The percentages reduction were 42.9 %, 64.3 %, 14.3 %, and 21.4 % for the samples with 30 % TiO2, 70 % TiO2, 100 % TiO2, and 100 % Ag, respectively, considering pure DLC films. CL1 increased 40 %, 220 % 240 %, and 160 % for 30 % TiO2, 70 % TiO2, 100 % TiO2, and 100 % Ag, while CL2 increased 30 %, 170.6 %, 100 %, and 152.9 % for 30 % TiO2, 70 % TiO2, 100 % TiO2, and 100 % Ag, compared to pure DLC films. There was a slight reduction in the hardness values of the films containing NPs compared to pure DLC or with only water. All films were classified as HF1 or HF2, by the VDI 3198 standard.