Corrosion and wear resistance of SiC:Cu:a-C composite films prepared by magnetron sputtering

SiC:Cu:a-C composite films were prepared by the RF magnetron sputtering technique, and the effects of different SiC contents on the structure and properties of the films were investigated. Results show that when the SiC sputtering power is 250 W, the corrosion current density is as low as 3.81 × 10−8 A·cm−2, which is three orders of magnitude lower than that of the pure Cu substrate. The average friction coefficient of the film is as low as 0.08. Further analysis shows that the increase in hydrocarbon and graphite-like structure in the composite films leads to a lower surface energy and polarization intensity with the rise in SiC sputtering power. Moreover, the papillae-structured with gradually increasing surface roughness of the film makes it more stable in contact with water droplets, which results in the excellent hydrophobic properties of the film. Meanwhile, more nano-SiC particles are uniformly dispersed in the composite films, which inhibits the growth of Cu grains and reduces the porosity in the film. Ultimately, the corrosion resistance of the film is improved. The nanocomposite structure formed in the film tightens the bond and reduces the shedding of SiC particles and three-body abrasive wear during the frictional wear process. The increased degree of graphitization in the film is beneficial to reduce the coefficient of friction.