【摘要】 利用放电等离子烧结（Spark plasma sintering,简称SPS）技术并配合机械加工的方式制备了3种相对摩擦工作面石墨取向为0°、45°和90°的铜基粉末冶金摩擦材料。采用MM1000-Ⅱ型惯性制动试验台测试了3种材料的制动摩擦磨损性能，并对其试验后的摩擦表面三维形貌特征、近摩擦面区域特征、磨屑特征和摩擦表面物相进行分析，研究了石墨排列取向对不同制动条件下铜基粉末冶金材料摩擦磨损性能的影响。结果表明：与石墨取向为0°的材料相比，石墨取向为45°和90°的材料的硬度、导热系数均显著提升。随着制动初速度的升高，3种材料的平均摩擦系数均呈现先上升后下降的趋势；在相同的制动条件下，石墨取向为45°和90°的材料的平均摩擦系数与石墨取向为0°的材料相差不大，但磨损率较低，特别是0.8 MPa、250 km/h条件下石墨取向为90°的材料的磨损率仅为石墨取向为0°的材料的31.8%。提高制动初速度均能够促进3种材料摩擦表面形成氧化膜，对于石墨取向为0°的材料，表面形成以Fe₃O₄为主的氧化膜，而对于石墨取向为90°的材料，则形成以Fe₂O₃为主的氧化膜。更多还原

【Abstract】 Three copper-based powder metallurgy friction materials with graphite orientations of 0°, 45° and 90° relative to friction working surface were prepared by spark plasma sintering（SPS） technology and mechanical machining. The braking friction and wear properties of the three materials were tested using the MM1000-II inertial braking test bench, and the three-dimensional morphology characteristics of friction surface, near friction surface area characteristics, debris characteristics and friction surface phase of the three materials after the test were analyzed. The influence of graphite orientation on the friction and wear properties of the copper-based powder metallurgy materials under different braking conditions was studied. The results show that compared with the materials with graphite orientation of 0°, the materials with graphite orientation of 45° and 90° have significantly improved hardness and thermal conductivity. With the increases of initial braking speed, the average friction coefficients of all three materials show a trend of first increasing and then decreasing. Under the same braking conditions, the average friction coefficient of the materials with graphite orientation of 45° and 90° is not significantly different from that of the materials with graphite orientation of 0°, but the wear rate is relatively low, especially at 0.8 MPa and 250 km/h, the wear rate of the materials with graphite orientation of 90° is only 31.8% of that of the materials with graphite orientation of 0°. Increasing the initial braking speed can promote the formation of oxide films on the friction surfaces of the three materials. For the material with graphite orientation of 0°, an oxide film mainly composed of Fe₃O₄ is formed on the surface, while for the material with graphite orientation of 90°, an oxide film mainly composed of Fe₂O₃ is formed.更多还原