氧化铝纤维含量对陶瓷基摩擦材料性能的影响

以工业废渣粉煤灰作为主要陶瓷组分,氧化铝纤维为增强相,采用冷压成型-热压固化两步法制备了氧化铝纤维增强陶瓷基摩擦材料,通过定速式摩擦磨损试验机研究了氧化铝纤维含量对陶瓷基摩擦材料性能的影响规律,并借助SEM观察磨损后样品的表面形貌,揭示了其摩擦磨损机理。结果表明:随着氧化铝纤维含量的增加,陶瓷基摩擦材料的孔隙率与密度不断增加,而硬度则先降低后上升然后再略降低；摩擦系数随氧化铝纤维含量的增加呈现出先降低后上升的趋势,当氧化铝纤维含量为25%时,样品的摩擦系数稳定在0.60左右；添加氧化铝纤维促进了陶瓷基摩擦材料的磨损,且随其含量增加,磨损率总体上呈增大趋势；未添加氧化铝纤维的陶瓷基摩擦材料磨损形式主要为磨粒磨损和接触疲劳磨损,而添加25%氧化铝纤维的陶瓷基摩擦材料磨损形式以磨粒磨损、粘着磨损和纤维的脆性断裂为主。

Effect of Alumina Fiber Content on the Performance of Ceramic-matrix Friction Materials

In the present study, cold press molding and thermocompression were carried out to prepare different contents of alumina fiber reinforced ceramic-matrix friction materials in terms of industrial waste residue fly ash as the main ceramic component. The effect of alumina fiber content on the performance of ceramic-matrix friction material was carefully studied by a constant speed friction tester. The surface morphology of specimens after wear were observed by SEM, and wear mechanism was also revealed. The results showed that with the increase of the content of alumina fiber, the porosity and density of ceramic-matrix friction materials were rising, and the hardness decreased first, then rose and again decreased slightly. The friction coefficient for alumina fiber reinforced ceramic-matrix friction materials has shown the trend of decreasing first and then rising. When the content of alumina fiber was 25%, the friction coefficient could be stable at 0.60. In addition, the addition of alumina fiber increased the wear rate of ceramic-matrix friction materials, and the wear rate increased with the increase of the content of alumina fiber. The results of SEM analysis showed that the main wear mechanism of ceramic-matrix friction material without adding alumina fiber was abrasive wear and fatigue wear. However, the main wear mechanism of ceramic-matrix friction material with adding the content of 25% alumina fiber was abrasive wear, adhesion wear and fiber brittle fracture.