Kim Il-Young, Lee Young-Ze
Department of Mechanical Engineering, Sungkyunkwan University, 300 Cheoncheon-dong, Jangan-gu, Gyeonggi-do 440-746, Republic of Korea.
J Nanosci Nanotechnol. 2011 Jan;11(1):335-8. doi: 10.1166/jnn.2011.3189.
Carbon nanotubes are considered the best material in the field of composites because of their mechanical and tribological properties. In this study, carbon nanotubes coated metal was dispersed in aluminum, the base metal, to improve the wettability between aluminum and carbon nanotubes. The friction and wear behaviors of the aluminum-carbon nanotube coated metal, which is a nickel and copper composite, were investigated using a pin-on-disk wear tester under dry sliding and water lubricated conditions and evaluated using SEM and EDX analysis. All the results demonstrated that the addition of the carbon nanotubes coated metal significantly improved the wettability of CNTs in the aluminum. And the distribution of CNTs prevented the propagation of micro cracks on the surface of the aluminum base metal sample, resulting in enhanced friction characteristics and wear resistance of the nano composite. The composite exhibited lower friction coefficient and wear resistance under the water lubricated condition than the dry sliding condition. Although the lubrication and cooling effect of water contributed to the reduction of the friction coefficient of the composite, the separation of wear particles from the sliding surface changed the wear type from three-body to two-body, resulting in very high wear rate. Also the concentration of oxide under water lubricated condition contributed to the increase of the wear rate because the amount of oxide film removed in terms of thickness exceeded the critical thickness of real contact area.
由于其机械和摩擦学性能，碳纳米管被认为是复合材料领域中最好的材料。在本研究中，将碳纳米管涂层金属分散在作为基体金属的铝中，以改善铝与碳纳米管之间的润湿性。使用销盘式磨损试验机在干滑动和水润滑条件下研究了镍和铜复合材料铝 - 碳纳米管涂层金属的摩擦和磨损行为，并使用扫描电子显微镜（SEM）和能谱分析（EDX）进行评估。所有结果表明，添加碳纳米管涂层金属显著改善了碳纳米管在铝中的润湿性。并且碳纳米管的分布阻止了铝基金属样品表面微裂纹的扩展，从而提高了纳米复合材料的摩擦特性和耐磨性。该复合材料在水润滑条件下比干滑动条件下表现出更低的摩擦系数和更好的耐磨性。尽管水的润滑和冷却作用有助于降低复合材料的摩擦系数，但磨损颗粒从滑动表面分离使磨损类型从三体磨损变为二体磨损，导致磨损率非常高。此外，水润滑条件下氧化物的浓度导致磨损率增加，因为就厚度而言去除的氧化膜量超过了实际接触面积的临界厚度。
