Effect of pore structure on mechanical and tribological properties of paper-based friction materials

To explore the effect of the pore structure of paper-based friction materials on the friction and wear properties, the composites with different pore structures were obtained using physical foaming technology. Results displayed that the bulk density and average pore size of composites increased after the foaming treatment, while the total pore area and porosity showed a tendency to gradually decrease after hot pressing. The tensile and interlaminar shear strength of the composites were improved by 18% and 42% respectively after the optimization of the pore structure. Moreover, the application of foaming technology significantly increased dynamic friction coefficient and reduced wear rate of the friction materials. In particular, the wear rate of paper-based friction materials decreased by 44.6% from 1.57x10⁻⁸ cm³/J to 0.87x10⁻⁸ cm³/J with the increase of foaming agent content. Most importantly, the pore structure of paper-based friction materials can be effectively changed due to the introduction of physical foaming technology. This research lays a solid foundation for optimizing the pore structure of paper-based friction materials in the future.