磁控溅射非晶碳基薄膜的结构设计与机械性能

发布时间：2018-04-13 07:57

本文选题：非晶碳 + 梯度复合薄膜　；参考：《浙江大学》2014年硕士论文

【摘要】：非晶碳(a-C)薄膜具有低的摩擦系数、高的硬度、优异的耐磨性能以及良好的生物相容性,在摩擦学和生物医学等领域具有很大的应用前景。然而,膜生长过程中产生的高内应力和高硬度容易导致薄膜的结合失效,限制其在表面保护工程方面的实际应用。本文把元素掺杂、功能梯度结构、多层结构应用于非晶碳基薄膜的设计当中,并探索了薄膜组织结构和机械性能的变化规律与内在机理。采用磁控溅射法制备出厚度约为1.5μm的含钛非晶碳复合薄膜,并将偏压梯度(bias-graded,从-20V逐渐变化到-150V)成功应用于该薄膜的结构设计中。研究发现,偏压梯度对含钛非晶碳膜层中的TiC没有太大的影响,但是偏压梯度薄膜的内应力和sp3碳含量均有所降低,与常偏压薄膜相比,偏压梯度薄膜不仅能维持较高的硬度(约19GPa),还具有良好的韧性与结合强度。在1ON高载荷条件下,偏压梯度复合薄膜在空气中的摩擦系数和磨损率分别约为0.08和2.89×10-16m3N-1m-1；而在Hanks'溶液中的摩擦系数也为0.08,但磨损率低至4.63×10-17m3N-1m-1,展现出良好的耐磨性能,Hanks'溶液提供了明显的润滑效果。通过非平衡磁控溅射设备系统沉积制备a-C/a-C:Ti纳米多层薄膜和a-C薄膜,对a-C/a-C:Ti纳米多层薄膜进行初步探索。研究发现,与a-C薄膜相比,该纳米多层薄膜的硬度高达25GPa,且具有良好的韧性。由于TiC纳米晶粒和大量界面的存在,薄膜的硬度和结合强度得到很大改善。另外,在无外界润滑条件下,该多层薄膜的摩擦系数和磨损率分别约为0.080和1.95×10-16m3N-1m-1；而在Hanks'溶液中,其摩擦系数和磨损率则分别低至0.074和4.25×10-17m3N-1m-1。通过沉积不同调制周期(12-70nm)的a-C/a-C:Ti纳米多层薄膜,对多层薄膜进行更深入的研究。结果表明,这一系列薄膜厚度均达到3μm左右,展现出良好的膜基协调能力和高的承载能力,随着调制周期的减小,a-C/a-C:Ti纳米多层薄膜的力学性能和摩擦学性能逐渐变好,调制周期为12nm的多层薄膜具有最高的结合强度、硬度(26GPa)、弹性模量(231.5GPa)、最低的摩擦系数(0.093)和磨损率(8.06×10-17m3N-1m-1)。
[Abstract]:Amorphous carbon monoxide (AC-C) thin films have high friction coefficient, high hardness, excellent wear resistance and good biocompatibility, so they have great application prospect in tribology and biomedicine.However, the high internal stress and high hardness produced during the growth of the film can easily lead to the failure of the film binding, which limits its practical application in the field of surface protection engineering.In this paper, elemental doping, functionally gradient structure and multilayer structure are applied to the design of amorphous carbon-based films. The changes of microstructure and mechanical properties of the films are discussed.Ti-containing amorphous carbon composite films with thickness of about 1.5 渭 m were prepared by magnetron sputtering. The bias-graded bias gradient was gradually changed from -20V to -150V) and successfully applied to the structural design of the films.It is found that the bias gradient has little effect on TiC in the amorphous carbon film containing titanium, but the internal stress and sp3 carbon content of the biasing gradient film are decreased, compared with that of the conventional bias film.The bias gradient film can not only maintain high hardness (about 19 GPA), but also have good toughness and bonding strength.Under the condition of high load of 1ON,The friction coefficient and wear rate of the bias gradient composite film in air are about 0.08 and 2.89 脳 10-16 m3N-1m-1, respectively, and the friction coefficient in Hanks' solution is 0.08, but the wear rate is as low as 4.63 脳 10-17m3N-1m-1.A-C/a-C:Ti nanocrystalline multilayer films and a-C thin films were prepared by unbalanced magnetron sputtering equipment, and the a-C/a-C:Ti nanocrystalline multilayer films were preliminarily explored.It is found that compared with a-C film, the hardness of the nanocrystalline multilayer film is as high as 25GPaand has good toughness.Due to the existence of TiC nanocrystals and a large number of interfaces, the hardness and bonding strength of the films were greatly improved.In addition, the friction coefficient and wear rate of the multilayer film are about 0.080 and 1.95 脳 10 ~ (-16) m ~ (3N-1m ~ (-1)) without external lubrication, while in Hanks' solution, the friction coefficient and wear rate are as low as 0.074 脳 10 ~ (-17) m ~ (-3) N ~ (-1) m ~ (-1) and 4.25 脳 10 ~ (-17) m ~ (3) N ~ (-1) m ~ (-1) respectively.By depositing a-C/a-C:Ti nanocrystalline multilayer films with different modulation periods (12-70 nm), the multilayer films were studied.The results show that the thickness of these films is about 3 渭 m, showing good coordination ability and high bearing capacity. With the decrease of modulation period, the mechanical properties and tribological properties of a-C / a-C: ti nanomultilayer films become better and better.The multilayer films with a modulation period of 12nm have the highest bonding strength, the hardness is 26 GPA, the elastic modulus is 231.5 GPaA, the lowest friction coefficient is 0.093) and the wear rate is 8.06 脳 10-17m3N-1m-1.
【学位授予单位】：浙江大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TB383.2

【参考文献】