掺硼类金刚石涂层的制备及结合强度研究

发布时间：2018-03-02 17:18

本文选题：类金刚石涂层　切入点：硼掺杂　出处：《上海工程技术大学》2015年硕士论文　论文类型：学位论文

【摘要】：通常把一系列含有sp3和sp2杂化的不稳定的非晶碳膜统称为类金刚石薄膜(DLC),这类薄膜具有高的硬度,低的摩擦因数,优异的耐磨性,良好的光学透过性和生物相容性,是近年来引起广泛重视的一种新型功能薄膜材料。并且掺B类金刚石涂层可以做成BDD电极,BDD电极具有高的析氧电位、低的背景电流、吸附惰性等特性,因而成为电化学电极的优良之选。但是类金刚石薄膜存在内应力过高、热稳定性差、脆性大、不能大面积沉积、摩擦磨损机理不完善的缺陷,国内外学者通过金属和非金属掺杂、多层膜结构设计等方法来降低薄膜内应力,提高热稳定性能;通过制备方法的改变来实现大面积沉积;通过不同条件下的摩擦行为来分析其摩擦磨损机理;这些解决办法均是在复合镀膜技术的“五化”思想(沉积技术复合化,涂层组成多元化,晶体结构纳米化,组成和结构多层化/梯度化)上衍生出来的。膜基结合力强弱是决定涂层寿命的关键因素,也是决定所有涂层应用价值的最基础因素。DLC涂层结合强度不高,一直是困扰其进一步应用的难题之一。目前主要通过元素掺杂、过渡层制备、纳米调制等手段来提高其结合力。其中硼掺杂类金刚石涂层的研究主要集中在电化学和生物相容性方面,对膜基结合力其最基础的力学性能鲜有研究,因此研究掺硼类金刚石涂层这方面性能不仅能解决其最基本的问题,而且能扩宽其应用途径。本课题主要采用磁控溅射方法制备类金刚石涂层,首先采用射频磁控溅射法在不同基底材料上制备了类金刚石涂层,分析了基底材料对涂层结构及膜基结合力的影响;其次采用闭合场非平衡磁控设备在不同石墨靶电流下制备了类金刚石涂层,通过原子力显微镜、扫描电镜、拉曼光谱、X衍射等方法分析了其微观形貌与结构,通过纳米压痕、划痕测试、摩擦磨损表征了其性能;最后采用固体硼作为溅射靶材制备了掺硼DLC涂层,采用多种检测方法分析了其微观结构及表征了其性能,分析硼元素对DLC涂层的影响。结果表明:射频磁控溅射和闭合场非平衡磁控溅射制备的类金刚石涂层,采用后者制备的涂层sp2键含量更高,膜基结合力更好,摩擦系数很低,一般在0.10以下;掺杂硼元素使得类金刚石涂层的表面粗糙度降低,sp2键含量增多;少量的硼元素可以使涂层弹性模量和硬度均提高,膜基结合力也小范围提高,摩擦系数降低,磨损率降低;但是硼元素过多,涂层弹性模量、硬度和膜基结合力均大大下降。
[Abstract]:A series of unstable amorphous carbon films containing sp3 and sp2 hybrids are commonly referred to as diamond-like carbon films with high hardness, low friction coefficient, excellent wear resistance, good optical transmission and biocompatibility. It is a new functional thin film material which has attracted much attention in recent years, and B-doped diamond coating can be made into BDD electrode with high oxygen evolution potential, low background current, adsorption inertia and so on. But the diamond-like carbon film has the defects of high internal stress, poor thermal stability, large brittleness, no large area deposition, imperfect friction and wear mechanism. Scholars at home and abroad reduce the internal stress and improve the thermal stability of the films by metal and non-metal doping, multilayer structure design and so on, and achieve large area deposition by changing the preparation methods. The mechanism of friction and wear is analyzed by friction behavior under different conditions. These solutions are based on the "five" idea of composite coating technology (composite deposition technology, coating composition diversity, crystal structure nanocrystalline, etc. Composition and structure of multilayer / gradient). The strength of membrane base adhesion is the key factor to determine the coating life and the most basic factor to determine the application value of all coatings. The bonding strength of DLC coating is not high. It has been one of the difficult problems for its further application. At present, it is mainly prepared by element doping and transition layer. The study of boron doped diamond-like carbon coatings is mainly focused on the electrochemical and biocompatibility, and the most basic mechanical properties of the films are rarely studied. Therefore, the study on the properties of boron doped diamond-like carbon coatings can not only solve its most basic problems, but also broaden its application. In this paper, diamond-like carbon coatings are prepared by magnetron sputtering. Firstly, diamond-like carbon coatings were prepared on different substrates by RF magnetron sputtering, and the effect of substrate materials on the structure and adhesion of the coatings was analyzed. Secondly, the diamond-like carbon coating was prepared by using closed field unbalanced magnetic control equipment under different graphite target currents. The microstructure and microstructure of the coating were analyzed by atomic force microscope, scanning electron microscope and Raman spectrum X-ray diffraction. The properties of the coatings were characterized by scratch test, friction and wear. Finally, boron doped DLC coatings were prepared by using solid boron as sputtering target. The microstructure and properties of the coatings were analyzed by various methods. The effect of boron element on DLC coating is analyzed. The results show that the diamond-like carbon coatings prepared by RF magnetron sputtering and closed field unbalanced magnetron sputtering have higher sp2 bond content, better adhesion and lower friction coefficient. Generally below 0.10, doping boron makes the surface roughness of diamond-like carbon coating decrease the content of sp2 bond, and a small amount of boron element can increase the elastic modulus and hardness of the coating, increase the adhesion of film base in a small range, and decrease the friction coefficient. The wear rate decreased, but the elastic modulus, hardness and adhesion of the coating decreased greatly.
【学位授予单位】：上海工程技术大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TQ163;TB306

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