Influence of W content on microstructural, mechanical and tribological properties of sulfurized W-doped diamond-like carbon coatings
Influence of W content on microstructural, mechanical and tribological properties of sulfurized W-doped diamond-like carbon coatings
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DOI：
10.1016/j.surfcoat.2012.12.026
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发表时间：
2013-03
影响因子：
5.4
通讯作者：
W. Yue;Song Wang;Z. Fu;Xiaocheng Gao;Xiang Yu;Jiajun Liu
中科院分区：
文献类型：
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作者：
W. Yue;Song Wang;Z. Fu;Xiaocheng Gao;Xiang Yu;Jiajun Liu
采用先沉积W掺杂类金刚石（W doped diamond-like carbon，W-DLC）涂层，再进行低温离子渗硫处理的两步法制备了一系列渗硫W-DLC涂层。实现了具有最佳力学性能和摩擦学性能的硫化物涂层复合类金刚石的设计思想。利用扫描电子显微镜（SEM）、X射线光电子能谱（XPS）、扫描俄歇微探针（SAM）、X射线衍射（XRD）和拉曼光谱对样品进行了结构分析。采用纳米压痕仪和球盘摩擦磨损试验机对复合材料的力学性能和摩擦学性能进行了测试。结果表明，渗硫W-DLC涂层的显微组织、力学性能和摩擦学性能与W含量有显著的相关性。高含量的钨促进了碳化钨的形成，从而阻止了硫的扩散，提高了渗硫后钨类金刚石涂层的石墨化程度。渗硫后W-DLC涂层的硬度随W含量的增加而逐渐增加，但低于未渗硫的W-DLC涂层。渗硫W-DLC涂层的摩擦系数和磨损率随W含量的增加而降低。硫化27.7% W-DLC涂层具有最佳的摩擦学性能，摩擦系数和磨损率最低。其摩擦学机理是由于表层富含石墨和硫化物，具有较低的剪切强度，而底层W-DLC涂层具有较好的力学性能。
A series of sulfurized W doped diamond-like carbon (W-DLC) coatings were prepared using a two-step method as depositing W-DLC coating firstly, and then treated by low temperature ion sulfuration. A designing thought of a composite DLC with sulfide coating with optimized mechanical and tribological properties was realized. The structural analyses were performed on the scanning electron microscope (SEM), X-ray photoelectron spectroscope (XPS), scanning Auger microprobe (SAM), X-ray diffraction (XRD) and Raman spectroscope. The mechanical and tribological properties were evaluated by the nanoindenter and ball-on-disk friction and wear tester. The results show that the microstructures, mechanical and tribological properties of sulfurized W-DLC coatings exhibited a significant dependence on the W concentration. A high fraction of W in W-DLC coating promoted the formation of WC which could prevent the S diffusion and the extent of graphitization for sulfurized W-DLC coatings. The hardness of sulfurized W-DLC coating gradually increased with higher W concentration, and it was lower than that of the untreated W-DLC coating. The coefficient of friction and wear rate of sulfurized W-DLC coating were reduced with the increase of W content. The best tribological properties with the lowest friction coefficient and wear rate were achieved on sulfurized 27.7% W-DLC coating. The tribological mechanism was attributed to the graphite-rich and sulfide composite top layer with lower shear strength and combining a support of the sublayer W-DLC coating with better mechanical property.