Diamond-like Carbon Films Improve their Properties with the Incorporation of Crystalline Diamond Particles

Diamond-like carbon (DLC) has been widely studied due to its mechanical properties such as low friction coefficient, high hardness, and high adherence on different substrate materials. The unique combination of chemical and mechanical properties of DLC films has opened the possibilities for the electrochemical applications of these film materials. In this chapter, a review of DLC films with extremally high hardness and very resistant to corrosion by incoporating crystalline diamond (CD) particles during the deposition process will be presented. These films were for the first time developed in our laboratories and the characterization performed will be also showed. The studies carried out in our laboratories show CD-DLC films improving DLC and stainless steel electrochemical corrosion resistance. CD-DLC prevented aggressive ions from attacking metallic surfaces, becoming a potential candidate for an anti-corrosion material in industrial applications, like pipelines in petroleum industry. It was also investigated the influence of the diamond particle sizes on the electrochemical corrosion resistance of these films. The electrochemical parameters obtained from the potentiodynamic polarization curves and the impedance were correlationated with the qualitative sp3/sp2 ratio of the CD-DLC films obtained from Raman scattering spectroscopy. The results show that both protection efficiency and impedance increase with the decrease of ID/IG ratio. It means the increase of sp3 bonds in DLC films reduce its electrochemical corrosion, improving the electrochemical protection efficiency and the impedance. In addition, diamond crystallites bigger than the DLC grain size reduced the pitting corrosion, which is an indication of the chemical inertness of the CD-DLC coatings to the Cl− ions. The tribological behavior of these films under aggressive solution was also investigated. The presence of bigger CD particles increased the film roughness. In addition, these CD particles dem
isbn: 9781613247
Pages: xxx