利用中频非平衡磁控溅射技术在单晶硅基底上沉积了类石墨碳膜,采用Raman光谱、高分辨透射电子显微镜、原子力显微镜分析了薄膜微观结构和表面形貌;采用纳米压痕仪和CSM摩擦磨损试验机测试了碳膜力学性能和摩擦学性能.结果表明:利用中频非平衡磁控溅射技术沉积的碳膜是一种以sp~2键合碳为主、结构非晶、硬度适中、应力较低、表面粗糙度较大、摩擦性能优异的薄膜.脉冲占空比对薄膜微观结构和性能有显著影响,随着脉冲占空比的增大,Raman光谱D峰和G峰的强度比ID/IG先减小后增大,而硬度随脉冲占空比的增大却呈现出相反的变化趋势,即先增大后减小;大气氛围中的摩擦性能测试表明,本实验制备的薄膜具有优异的抗磨性能(~10~(-11)cm~3/N~(-1)·m~(-1))和承载能力(~2.5 GPa).随脉冲占空比的增大,薄膜摩擦系数变化甚微而磨损率却呈现先显著减小后轻微增大的变化趋势.类石墨碳膜优异的摩擦学性能主要归因于其独特的结构、较低的内应力及良好的结构稳定性.
A series of graphite-like carbon films is fabricated by the middle frequency magnetron sputtering technique. The microstructures and the morphologies of the resulting films are investigated by Raman spectroscopy, high resolution transmission electron microscopy and atomic force microscopy, respectively. The mechanical and the tribological properties of the films are studied by nanoindenta- tion and CSM tribometer. The results show that the deposited carbon film is dominated by sp2 sites, and has an amorphous struc- ture, a moderate hardness, low internal stress, high surface roughness and superior tribological properties. With the increase of the duty ratio, the intensity ratio between D and G peaks first decreases and then increases, while the film hardness first increases and then decreases. Tribological testing in humid atmosphere demonstrates that the present carbon film has a superior wear resistance (,-~10-11 cm3/N-l.m-1) and high load bearing capacity (~2.5 GPa). Although the duty ratio has no obvious influence on friction coefficient, the wear rate decreases obviously and then increases slightly with the increase of duty ratio. The superior tribological properties of the graphite-like carbon film are attributed mainly to its unique structure, low internal stress and high structure stability.