Wear Performance under Different Surface Morphology Based on SSiC-M120D Pair

The purpose of this paper was to study the friction and wear properties of friction pairs with different surface shapes in the same test environment, and to find the best way to construct the surface morphology of pairs. By studying the influence of the coupling mode of laser engraving surface texture and diamond film plating on the friction properties of silicon carbide and graphite pairs, the synergistic mechanism of structured pattern groove and diamond film was deeply studied. Firstly, non-texture diamond films (SSiC-D) and spiral groove textured composite diamond films (SSiC-DC) were prepared on pressureless sintered silicon carbide (SSiC) surfaces by laser processing textured patterns and hot filament chemical vapor deposition (CVD). Then, the friction coefficient, surface temperature rise and wear rate of SSiC-M120D, SSiC-D/M120D and SSiC-DC/M120D under different surface morphology were studied on a friction machine. The worn surface of the tested sample was investigated by scanning electron microscope (SEM) and EDS energy spectrum, and the wear mechanism was analyzed by Raman spectroscopy and XRD diffractometer. The results showed that the degree of adhesive wear and abrasive wear on the friction surface of silicon carbide samples coated with diamond film was significantly reduced, the content of carbon element was still more than 90%, and the friction coefficient of SSiC-D/M120D and SSiC-DC/M120D were significantly reduced, so that the friction surface roughness of SSiC-D and SSiC-DC were much smaller than that of SSiC, indicating that the surface of diamond film samples was smoother because of the lower roughness of the coating. The lubrication effect was also good, which weakened the occlusal action between the contact surfaces of the friction pair and reduced the friction coefficient obviously. At the same time, the end face temperature rise could be effectively controlled. The end face temperature of SSiC-D/M120D and SSiC-DC/M120D were 64.3 and 61.2 ℃, which were 60.11% and 62.03% lower than that of SSiC/M120D 161.2 ℃. The wear rate of SSiC-DC/M120D measured after the test is only 2.8×10⁻⁷ g/(N·m), indicating that the surface microtexture further improved the heat dissipation condition of the friction surface of the diamond film sample, which was helpful to alleviate the mechanical action of the friction pair in the friction area. The lubrication system composed of diamond film and abrasive debris in the friction surface had better anti-friction and anti-wear performance. It could effectively reduce the friction and wear on the surface of silicon carbide and prolong its service life. After the test, the ratio of I_D/I_G at the wear mark was only 0.86 and 0.94, and the degree of surface defect was small. The XRD diffraction peak intensity of SSiC-DC/M120D with spiral groove texture composite diamond film was the lowest and had the best tribological properties. Micro-texture was conducive to heat dissipation and storage of debris, which could further reduce surface adhesive wear, and the wear rate was the lowest after the test. In this paper, combined with the advantages of surface micro-nano texture and thin film, laser ablation and hot filament CVD coating technology were used to form SSiC surface composite modeling, which was of positive significance to explore the construction of surface morphology of friction pairs.