Structure and tribological properties of amorphous carbon films deposited by electrochemical method on GCr15 steel substrate

Amorphous carbon films were deposited on GCr15 steel substrates by electrolysis of methanol, dimethylsulfoxide (DMSO) and the methanol-DMSO intermixture electrolytes, respectively, under high voltage and low temperature conditions. The microstructure and wear morphology of the deposited films were analyzed using X-ray diffraction (XRD), Raman spectroscopy and scanning electron microscopy (SEM) combined with energy dispersive X-ray fluorescence spectrometer (EDX), respectively. The tribological properties of the films were evaluated using a ball-on-disk rotating friction tester under dry friction condition. The results show that the films deposited by electrodeposition technique on GCr15 steel substrates are amorphous carbon films. It is also found that the electrolytes have an obvious influence on the tribological properties of the deposited films with the electrodeposition method. The tribological properties of the films deposited with the intermixture electrolyte are better than those of the films deposited by other pure electrolytes. The related growth mechanism of the films in the liquid-phase electrodeposition is discussed as well in this study. Via the reaction of the CH₃ groups with each other to form carbon network and reaction of the CH₃ and SO²⁺ groups to achieve the doping of sulfur atom in the carbon network, respectively, in other words, amorphous carbon films can be obtained on GCr15 steel substrates by electrodeposition technique.