Cailiao Baohu (Jun 2024)
Effect of Substrate Surface Roughness on the Friction and Wear Properties of Amorphous Carbon Films
Abstract
In order to investigate the effect of different substrate surface roughness on the friction and wear properties of amorphous carbon films, and improve the tribological properties of the 2Cr13 sample surface under 601EF lubricating grease lubrication, the methods such as machining, polishing and other techniques were employed to prepare different surface roughness on the surface of 2Cr13 samples. Subsequently, amorphous carbon thin films were prepared on the surface of samples with different roughness by magnetron sputtering. The friction and wear properties of amorphous carbon films and silicon nitride balls under 601EF lubricating grease lubrication were investigated through ball-disc contact friction and wear tests, and the wear places were analyzed by optical microscopy. Results showed that the Si3N4 balls that rubbed against the substrate surface all presented a clear platform, while the substrate surface did not display any obvious grinding marks. The samples with the Ra range of 0.20～0.75 μm on the coupling ball had the smaller wear amount, the wear spot area range was 0.152～0.165 mm2, and the wear form was adhesive wear. By contrast, the samples with the Ra range of 0.95～3.19 μm had more wear amount on the coupling ball, the wear spot area ranging from 0.228～0.275 mm2, and there were furrow-like wear marks, which indicated more serious wear. Under the same operating conditions, as the surface roughness of the substrate increased, the starting and average friction coefficients between the two friction pairs, as well as the wear amount of Si3N4 balls, all showed a trend of first decreasing, then increasing, and then decreasing. When the Ra was 0.56 μm, the tribological performance of the amorphous carbon film was the best, and the friction curve was relatively stable, with an average friction coefficient of 0.162, and the wear amount of its coupling ball was the smallest, 0.152 mm2. In general, the surface roughness of the substrate affected the tribological performance of amorphous carbon films, and the surface with good anti friction properties could be obtained by preparing appropriate roughness on the substrate surface via the means of machining, polishing, etc.
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