气孔率对湿式纸基摩擦材料性能的影响

Effect of Porosity on the Performance of Paper-based Wet Friction Material

关键词:  湿式纸基摩擦材料  气孔率  压缩回弹性  导热性  摩擦磨损性能

Key Words:paper-based wet friction materials  porosity  compression and recovery property  thermal conductivity  friction and wear performance

摘要:制备了由芳纶浆粕增强的气孔率不同的3种湿式纸基摩擦材料，采用改进油浸法测定湿式纸基摩擦材料的气孔率，探究了气孔率对湿式纸基摩擦材料的压缩回弹性、导热性、黏弹性以及摩擦磨损性能的影响。结果表明，随着气孔率的增大，湿式纸基摩擦材料的压缩率升高，回弹率降低，导热系数增大，达到0.998 W/（m·K），损耗因子tanδ也升高；随着气孔率的增大，湿式纸基摩擦材料摩擦因数增大，但摩擦因数的稳定性降低；虽然磨损率会随气孔率的增大而升高，但芳纶浆粕的加入，使磨损率远低于国家标准。湿式纸基摩擦材料气孔率为41.92%时，压缩率为17.50%，回弹率为55.47%，导热系数为0.565 W/（m·K），动、静摩擦因数分别为0.125、0.135，磨损率为1.23×10^-8 cm³/J，摩擦过程也较为平稳。综合分析，湿式纸基摩擦材料的气孔率控制在40%左右时各性能最均衡。

Abstract:Three groups of paper-based wet friction materials enhanced by aramid pulp with different porosity were prepared. The porosity of the samples was determined by improved oil immersion method. The effects of porosity on compression recovery property, thermal conductivity, viscoelasticity, friction and wear performance of paper-based wet friction materials were investigated. The results showed that, with the increase of porosity, the compressibility increased, the recovery rate became lower, the thermal conductivity increased to 0.998 W/（m·K）, and the loss factor tanδ also increased. As the porosity increased, the friction coefficient of the sample improved, but the stability of the friction coefficient decreased. Although the wear rate increased with the increase of porosity, the addition of aramid pulp resulted in a wear rate that was far lower than the national standard. When the porosity of sample was 41.92%, the compressibility was 17.50%, the recovery rate was 55.47%, the thermal conductivity coefficient was 0.565 W/（m·K）, the dynamic and static friction coefficients were 0.125 and 0.135 respectively, and the wear rate was 1.23×10^-8 cm³/J， and the friction process was also stable. In summary, the porosity of paper-based wet friction materials should be controlled at about 40% to achieve the optimal performance．