Fe_3Al-Cu基刹车材料的制备及其摩擦学特性

Preparation and tribology properties of Fe_3Al-Cu base brake materials

采用机械合金化结合热压烧结法制备了一种新型Fe3Al Cu基刹车材料, 并对其力学性能及摩擦学特性进行了研究。结果表明, 相比Fe基材料, Fe3Al Cu基刹车材料密度小, 强度高, 随着Cu含量的增加(6% ~30%,质量分数), 其硬度和强度降低, 摩擦系数和磨损率都升高。Cu含量为 12% ~18%时摩擦系数高而稳定, 耐磨性好, 此时摩擦系数为 0 5~0 55, 平均磨损率约 1 5×10-5 mm3·N-1·m-1。不同阶段材料的摩擦磨损机制不同,摩擦初期以磨粒磨损为主; 中期主要包括塑性变形、裂纹扩展和疲劳断裂; 后期主要是氧化磨损, 当Cu含量过高时(大于 24% )会发生粘着磨损。

New Fe_3Al-Cu base brake materials were prepared by mechanical alloying and hot pressing. The mechanical properties and dry sliding tribological properties were studied. The results show that in this experiment, compared with Fe-based material, Fe_3Al-Cu based brake materials have lower density and higher strength. With the increase of Cu content (6%30%), the hardness and strength of brake materials decrease, and the friction coefficient and wear rate increase. The brake materials with 12%18% Cu have high and smooth friction coefficient, and excellent wear resistance, the friction coefficient of which is 0.500.55 and the average wear rate is about 1.5×10^(-5)mm^3/(N·m). There are different wear mechanisms during different friction stages. The first period is mainly abrasive wear, the latter includes plastic deformation, crack propagation and fatigue fracture, and the last is oxidation wear. When the content of Cu is more than 24%, the adhesion of brake material to the counterpart takes place, which leads to serious wear.