Tribological behaviour of titanium carbide/amorphous carbon nanocomposite coatings: From macro to the micro-scale
Tribological behaviour of titanium carbide/amorphous carbon nanocomposite coatings: From macro to the micro-scale
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DOI：
10.1016/j.surfcoat.2008.02.012
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发表时间：
2008-05
影响因子：
5.4
通讯作者：
J. C. Sánchez-López;D. Martinez-Martinez-D.-Martinez-Martinez-1404808168;C. López-Cartes;Asunción Fernández
中科院分区：
文献类型：
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作者：
J. C. Sánchez-López;D. Martinez-Martinez-D.-Martinez-Martinez-1404808168;C. López-Cartes;Asunción Fernández
通过 PVD/CVD 技术制备的纳米晶金属碳化物和非晶碳 (a-C) 纳米复合涂层的摩擦学行为非常依赖于薄膜沉积技术、合成条件和测试参数。本文以 TiC/非晶碳基纳米结构体系为重点，致力于评估控制该纳米复合材料家族摩擦学性能的因素，使用磁控溅射技术制备的一系列 TiC/a-C 薄膜，改变每个靶材（钛或石墨）的功率，作为模型系统，建立薄膜微观结构和化学成分之间的相关性，以及通过钉盘摩擦计测量的摩擦学性能。通过透射电子显微镜 (TEM) 观察到，薄膜的微观结构从准多晶 TiC 转变为由嵌入无定形碳基体中的 TiC 纳米晶体形成的纳米复合材料。纳米晶/非晶比似乎是控制摩擦学性能的关键参数，其量化已通过电子能量损失谱（EELS）完成。对于无定形碳相含量高于 60-65% 的纳米复合材料，观察到摩擦性能发生显着变化。摩擦系数从 0.3 降至 0.1，薄膜磨损率降低了 10 倍。通过激光显微拉曼光谱检查球和薄膜表面的磨痕，可以确定是否存在金属氧化物和碳质化合物，这些金属氧化物和碳质化合物是造成观察到的摩擦行为的原因。根据所获得的结论对文献结果进行的修订能够解释它们在摩擦学性能方面的明显分散。
The tribological behaviour of nanocomposite coatings made of nanocrystalline metal carbides and amorphous carbon (a-C) prepared by PVD/CVD techniques is found to be very dependant on the film deposition technique, synthesis conditions and testing parameters. Focusing in the TiC/amorphous carbon-based nanostructured system, this paper is devoted to an assessment of the factors governing the tribological performance of this family of nanocomposites using a series of TiC/a-C films prepared by magnetron sputtering technique varying the power applied to each target (titanium or graphite) as model system to establish correlations between film microstructure and chemical compositions and tribological properties measured by a pin-on-disk tribometer. The film microstructure goes from a quasi-polycrystalline TiC to a nanocomposite formed by nanocrystals of TiC embedded in an amorphous carbon matrix as observed by transmission electron microscopy (TEM). The nanocrystalline/amorphous ratio appears to be the key-parameter to control the tribological properties and its quantification has been done by electron energy-loss spectroscopy (EELS). A significant change in the tribological performance is observed for nanocomposites with amorphous carbon phase contents above 60–65%. The friction coefficient decreases from 0.3 to 0.1 and the film wear rates by a factor of 10. Examination of the wear scars on ball and film surfaces by laser micro-Raman spectroscopy has allowed to determine the presence of metallic oxides and carbonaceous compounds responsible of the observed friction behaviour. The revision of the literature results in view of the conclusions obtained enabled to explain their apparent dispersion in the tribological performance.