Study of the Influence of Counterbody Material on the Tribological Characteristics of Carbon Composites Based on Fabric Prepregs

The processes occurring on the contact surface during friction of experimental carbon–carbon composite materials reinforced with a carbon fabric based on polyacrylonitrile (PAN) and a viscose precursor were studied. Tribological tests of the composites were carried out on a tribometer using a ring–disk contact scheme. Two materials were used as counterbodies: hardened steel and silicon carbide ceramics. It has been established that the wear rate and friction coefficient under the load-speed modes used in operation mainly depend on the choice of the counterbody material. Heat treatment (carbonization or graphitization) and precursor material (PAN or viscose) also have an effect, but depending on the selected counterbody. It is shown that when tested with a ceramic counterbody, the tribological characteristics (friction coefficient and wear resistance) are better compared to friction paired with a steel counterbody. The surfaces of counterbodies and composites were studied before and after tribological tests by scanning electron microscopy, X-ray spectral analysis, and optical profilometry. It is shown that during friction a film of secondary structures is formed on the surface of carbon composites from wear products. This is the determining factor that affects tribological characteristics. After testing with a steel counterbody, a significant amount of iron was found on the surface of the composites in the film, which indicated wear of the counterbody. This process negatively affects the tribological properties of the composites. At the same time, the ceramic counterbody practically does not wear out, which makes it a more preferable material for working in friction units paired with a carbon composite.