碳基薄膜的摩擦学性能及应用研究

发布时间：2018-11-27 14:57

【摘要】：本文利用中频磁控溅射和等离子体增强化学气相沉积技术在硅片和不同金属表面上制备了一系列的类金刚石薄膜。研究了工艺参数与薄膜结构和性能之间的相关性,并考察了薄膜在不同测试条件下的摩擦学性能,主要的研究成果如下： (1)利用中频磁控溅射沉积技术通过改变镍靶电流在单晶硅表面上制备了不同镍含量的掺镍类金刚石薄膜,并考察了镍含量对薄膜的结构和性能的影响。结果表明：镍元素的掺杂,能大幅降低薄膜的残余应力和提高薄膜与基底之间的结合力。当镍含量比较低时,薄膜表现出优异的摩擦学性能,但其机械性能却随着镍含量的增高而降低。 (2)利用等离子体增强化学气相沉积技术在316L不锈钢表面上制备了类金刚石薄膜,并考察了前驱气体流量比和沉积气压对薄膜的结构、机械性能和摩擦学性能的影响。结果表明：前驱气体流量比和沉积气压对所制备薄膜的结构和性能有着显著的影响。当CH4和H2流量比为20：10的时候,所制备的薄膜表现出优异的机械性能和摩擦学性能,薄膜的硬度和摩擦系数分别为25GPa和0.044;当沉积气压为15Pa时,所制备的薄膜表现出优异的机械性能,薄膜的硬度为18.4GPa,当沉积气压为31Pa时,所制备的薄膜表现出优异的摩擦学性能,摩擦系数为0.035。 (3)利用等离子体增强化学气相沉积技术在316L不锈钢表面上制备了类金刚石薄膜,并考察了薄膜在不同测试环境下的摩擦学性能。结果表明：随着载荷的增大,薄膜在空气中的摩擦系数逐渐减小,在水环境中的摩擦系数逐渐增大,在柴油环境中的摩擦系数先增大后减小。而随着滑动速度的增大,薄膜在空气、水和柴油环境中的摩擦系数都逐渐减小,且在空气中的摩擦系数最大,柴油环境中的摩擦系数最小。 (4)利用等离子体增强化学气相沉积技术在钛合金和316L不锈钢表面上制备了类金刚石薄膜,并考察了薄膜在不同润滑条件下的摩擦学性能。结果表明：在316L不锈钢表面上所制备的薄膜表现出优异的机械和摩擦学性能,表明了基底的材质对薄膜的结构和性能有着显著的影响。通过对薄膜在空气、合成机油和水环境中的摩擦学性能研究,表明了流体润滑的化学过程是一个需要被考虑的重要参数,且薄膜与合成机油接触时得到了最低的摩擦系数和磨损量。
[Abstract]:A series of diamond-like carbon (DLC) films were prepared on silicon and different metal substrates by intermediate frequency magnetron sputtering and plasma enhanced chemical vapor deposition. The correlation between the process parameters and the structure and properties of the films was studied, and the tribological properties of the films under different test conditions were investigated. The main research results are as follows: (1) Nickel doped diamond films with different nickel content were prepared on the surface of single crystal silicon by medium frequency magnetron sputtering deposition by changing the current of nickel target. The effects of nickel content on the structure and properties of the films were investigated. The results show that the residual stress of the films can be greatly reduced and the adhesion between the films and the substrate can be improved by doping with nickel. When the nickel content is low, the film exhibits excellent tribological properties, but its mechanical properties decrease with the increase of nickel content. (2) Diamond-like carbon (DLC) films were prepared on 316L stainless steel by plasma enhanced chemical vapor deposition. The effects of flow rate of precursor gas and deposition pressure on the structure, mechanical properties and tribological properties of the films were investigated. The results show that the precursor gas flow ratio and deposition pressure have a significant effect on the structure and properties of the films. When the flow ratio of CH4 and H2 is 20:10, the films exhibit excellent mechanical properties and tribological properties. The hardness and friction coefficient of the films are 25GPa and 0.044, respectively. When the deposition pressure is 15Pa, the films exhibit excellent mechanical properties, the hardness of the films is 18.4 GPA, and when the deposition pressure is 31Pa, the films exhibit excellent tribological properties, the friction coefficient is 0.035. (3) Diamond-like carbon (DLC) films were prepared on 316L stainless steel by plasma enhanced chemical vapor deposition technique. The tribological properties of the films were investigated in different test environments. The results show that with the increase of load, the friction coefficient of the film decreases in air, increases in water environment, and then decreases in diesel oil environment. With the increase of sliding speed, the friction coefficient of the film decreases gradually in air, water and diesel environment, and the friction coefficient in air is the largest, and the friction coefficient in diesel oil environment is the smallest. (4) Diamond-like carbon films were prepared on titanium alloy and 316L stainless steel by plasma enhanced chemical vapor deposition. The tribological properties of the films were investigated under different lubrication conditions. The results show that the films prepared on the surface of 316L stainless steel exhibit excellent mechanical and tribological properties, indicating that the substrate material has a significant effect on the structure and properties of the films. By studying the tribological properties of the film in air, synthetic oil and water environment, it is shown that the chemical process of fluid lubrication is an important parameter to be considered. The lowest friction coefficient and wear rate were obtained when the film was in contact with synthetic engine oil.
【学位授予单位】：兰州理工大学
【学位级别】：博士
【学位授予年份】：2013
【分类号】：TH117;TB383.2

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