Friction properties of bulk isotropic pyrocarbon materials based on different composite microstructures

The isotropic pyrocarbon bulk materials were prepared by the fixed-bed chemical vapor deposition method, and the internal structure was composed of ribbon-like structure and spherical structure together. The friction behaviors of isotropic pyrocarbon at room temperature were studied by characterizing the microstructure and friction morphology. The frictional properties of isotropic pyrocarbon are greatly influenced by internal ribbon-like pyrocarbon. With a higher content of ribbon-like pyrocarbon, the material produces a moderately rough friction film, which improves the stability of the friction coefficient. Meanwhile, ribbon-like pyrocarbon increases the hardness of the material and reduces its wear rate. In addition, external stress can impact the friction behavior of the material. Increasing the external load causes the friction film to become more continuous and uniform, reducing the overall friction coefficient of the material. When the load is low (50 N and 100 N), the friction coefficient tends to stabilizemore quickly. Nevertheless, an excessive load (200 N) will result in the creation of grooves, making it difficult to stabilize the friction coefficient of the material. (c) 2022 The Authors. Published by Elsevier B.V.