含氢类富勒烯碳薄膜制备及超滑性能研究进展

类富勒烯碳薄膜是一种由弯曲石墨烯镶嵌的非晶网络复合结构,正是由于这种弯曲石墨烯结构(类富勒烯结构)的存在,赋予了薄膜高的硬度,优异的弹性恢复和超低摩擦性能(摩擦因数为0. 002～0. 009)。综述含氢类富勒烯碳薄膜制备方法、纳米结构调控机制、超低摩擦学机制及后处理对薄膜摩擦学性能的影响;探讨含氢类富勒烯碳薄膜在汽车发动机方面的应用,指出其可有效降低发动机部件的摩擦磨损,有利于发动机的节能减排;总结氢类富勒烯碳薄膜未来工程应用的潜在挑战,指出类富勒烯碳薄膜虽在可控范围内具有超滑性能,但未来如何实现全工况范围超滑和固油复合超滑将是一个主要研究方向。     

温度对类富勒烯碳氮薄膜微观结构与摩擦学性能的影响

采用直流反应磁控溅射分别在200、250、300和350℃条件下沉积类富勒烯碳氮薄膜,利用X射线光电子能谱(XPS)和扫描电子显微镜(SEM)表征薄膜的微观结构形貌,采用薄膜综合性能测试仪以及通过大气球盘摩擦试验研究薄膜的力学性能及摩擦学性能。结果显示:制备的类富勒烯CN_x薄膜中存在sp~2C-C、sp~2N-C和sp~3C-N化学键;随着沉积温度的升高,薄膜的结构变得更加致密,硬度、弹性模量以及弹性恢复系数逐渐增大,摩擦因数和磨损率降低;沉积温度为350℃制备的薄膜摩擦因数和磨损率最低,表现出优异的耐磨损性能。     

过滤式阴极电弧沉积类金刚石薄膜的碳弧稳定性研究

介绍自行研制的一套过滤式阴极电弧沉积设备,并以石墨作为靶材进行类金刚石薄膜的沉积研究,碳弧本身的惰性限制了电弧的稳定性。电弧电压,磁场等对弧的稳定性有很大的作用。试验得到表面光滑的类金刚石薄膜,并对其进行了形貌分析。     

ECR-CVD制备类金刚石碳膜的正交实验法研究

采用系统的正交实验法对ECR-CVD法沉积类金刚石碳膜(DLC)的优化工艺进行研究,并分析不同工艺参数对DLC膜性能的影响.共选择基片温度、H2流量、微波功率、直流偏压、脉冲偏压以及脉冲偏压占空比6个参数建立起6因素5水平的正交表,分别以薄膜摩擦因数、磨损率、显微硬度、拉曼谱中D峰与G峰的面积比ID/IG作为考察对象进行研究.极差分析表明,对不同的考察因素其优化工艺略有区别.在所选的参数范围内,脉冲偏压对所测量的DLC膜的性能影响最大.     

类金刚石薄膜的光学性能的研究

利用脉冲真空电弧镀的方法,在硅基底上沉积类金刚石薄膜,研究薄膜的光学性能、光学常数和离子能量关系。结果表明:不同的离子能量可以得到不同折射率的薄膜,无氢类金刚石薄膜的折射率在2.5～2.7之间变化;通过改变工艺条件来制备不同折射率的薄膜,和不同折射率的基底材料相互匹配;折射率和光学能隙随离子能量具有相反的变化趋势,和理论预测的趋势相一致;对于硅、锗等红外材料,要求的薄膜应具有1.8～2.1左右的折射率,因此提出一种基于物理汽相沉积和化学汽相沉积两种相互结合的方法,来降低薄膜的折射率,以达到和硅、锗等材料的折射率匹配。     

类金刚石薄膜摩擦机理及其摩擦学性能影响因素的研究现状

类金刚石薄膜(DLC)具有十分优异的减摩耐磨性能,是一种极具发展潜力的固体润滑材料。但其摩擦学性能受到很多因素的影响,这些因素主要可以分为两大类:固有因素和外在因素。在不同的固有因素和外界因素影响下DLC薄膜的摩擦学性能会产生较大差异,这大大制约了人们对其摩擦学行为及摩擦机理的认识,限制了其应用范围的扩展。总结了目前有关DLC薄膜摩擦机理的三种理论,即转移膜理论、滑行界面石墨化理论和化学吸附钝化悬键理论,并在此基础上概括分析了各固有因素和外界因素对DLC薄膜摩擦学性能的影响及其机理,提出未来可以从基础理论和相关技术两方面对DLC薄膜的摩擦学性能展开深入研究。     

类金刚石薄膜水润滑摩擦学特性研究进展

综述类金刚石薄膜水润滑摩擦学特性的研究进展,评述薄膜在水环境中的摩擦磨损特性,分析薄膜种类、元素掺杂、对摩材料以及微结构对DLC薄膜水润滑摩擦学特性的影响,并阐述DLC薄膜在水中的摩擦磨损机制。指出:DLC薄膜水润滑摩擦学特性受薄膜制备参数和摩擦试验环境影响,通过与微结构的耦合可以进一步改善类金刚石薄膜的摩擦学特性。同时还展望了类金刚石薄膜水润滑摩擦学未来研究方向。     

类金刚石薄膜纳米摩擦性能的试验研究

利用摩擦力显微镜(FFM),对由等离子体增强化学气相法沉积的类金刚石(DLC)薄膜的纳米摩擦性能进行了试验研究。用原子力显微镜(AFM)观察了DLC薄膜样品的表面形貌,同时测定了其粘附力值。从外加载荷、扫描速度和湿度的角度分析了薄膜的摩擦特性。     

工艺条件对类金刚石薄膜在不同介质环境下摩擦学性能的影响研究

考察了基底负偏压对类金刚石薄膜(DLC)在无水和有水环境下摩擦性能的影响。利用电子回旋共振等离子体化学气相方法沉积制备DLC薄膜,利用激光拉曼(Raman)、原子力显微镜(AFM)和纳米硬度计表征了其结构特征,用UMT型多功能摩擦磨损实验机考察了其摩擦性能,并用光学显微镜分析了磨痕特征。结果表明:随着基底偏压的增加,表面粗糙度减小;在无水条件下,基底偏压较低的DLC薄膜摩擦因数较高,并存在一定的波动性,基底偏压较高时,摩擦因数较低。在有水条件下,基底偏压对摩擦因数影响不大。总体来说,加水后薄膜磨损较为严重。     

纳米结构碳基薄膜的制备及性能研究

利用单极脉冲等离子体增强化学气相沉积技术在单晶硅衬底上沉积含氢碳薄膜,用高分辨透射电子显微镜和激光拉曼光谱仪研究薄膜的微观结构,用X射线光电子能谱分析薄膜的化学键状态,并用纳米压痕仪测定薄膜的硬度和弹性模量,在CSM往复式摩擦磨损试验机上考察薄膜的摩擦学性能。结果表明:在单极脉冲等离子体增强化学气相沉积系统上成功制备出在非晶基体上镶嵌弯曲类富勒烯纳米结构的含氢碳薄膜,其独特的类富勒烯纳米结构赋予薄膜良好的力学性能,其弹性恢复系数和硬度分别高达86%和26.37 GPa;与非晶结构薄膜相比,制备的纳米结构含氢碳薄膜在室温环境下摩擦学性能更为优异,在机械摩擦表面具有广阔的应用前景。     

DLC薄膜的表面形貌及其摩擦学性能研究

以真空蒸发碳离子束辅助镀膜法制备了DLC薄膜，通过原子力显微镜(AFM)和扫描电子显微镜(SEM)观察了该薄膜的表面形貌，对该薄膜的表面形貌对其摩擦学行为的影响进行了研究。研究发现：用真空蒸发碳离子束辅助镀膜的方法制备的类金刚石薄膜表面光滑，颗粒均匀，粒度小，摩擦因数降低；DLC薄膜比弹簧钢片及Ti6Al4V球基体耐磨；DLC薄膜的摩擦学性能在摩擦过程中会进一步改善。     

Tribological Properties of Films Formed by the Reaction of Carbon Tetrachloride with Iron

The tribological properties of halide films grown on iron by reaction with carbon tetrachloride vapor at a temperature of 617 K and a pressure of 1.7 Torr are compared, in ultrahigh vacuum, with FeCl₂ films evaporated onto the surface. It is found that the reactively formed film has a slightly lower limiting friction coefficient than the evaporated layer (~0.06 compared to ~0.08), which may be due either to the diffusion of some carbon into the substrate or the formation of a more oriented layer when this is formed reactively. The major difference between the reactively grown and evaporated film is that the evaporated layer attains the minimum friction when ~40 ? of FeCl₂ has been evaporated, while the reactively formed layer has a minimum friction coefficient when a film of 6±2 ? has been deposited. In the case of the evaporated FeCl₂ film, the growth of second and subsequent layers proceeds before the first layer is complete. It has been shown that the friction coefficient reaches its minimum value after completion of the first monolayer, a process that is complete after the evaporation of ~40 ? of FeCl₂. In the case of the film formed by reaction with CCl₄, the halide film grows directly on the surface implying that the FeCl₂ monolayer thickness is ~6 ?. This value is in good agreement with the layer thickness in bulk ferrous chloride.     

Tribological Properties of Diamond-Like Carbon Films in Low and High Moist Air

Diamond-like carbon (DLC) film was deposited on Si wafer by a plasma CVD deposition system using benzene. Tribological properties of the DLC film were evaluated using a ball-on-disk tribo-meter in low (RH 1720 %) and high humidity (RH 9095 %) conditions in air. The effect of sliding speed (4.2 mm/s to 25 mm/s) and load (1.06 N to 3.08 N) on friction and wear was investigated. The friction behavior of the DLC film was obviously different in low and high humidity. When tested under low humidity conditions, the friction coefficient decreased significantly with increasing speed, and increased with load. However, under high humidity conditions, the friction coefficient increased with the speed and decreased with increasing load. The wear of the DLC film was little influenced by the sliding speed, normal load and humidity; a level of 10^-8 mm³/Nm could be obtained in all tests. The formation of a uniform transfer layer would be the main factor which controlled the friction coefficient of the DLC films. Unlike the friction, the wear resistance of the DLC film is not so easy to discuss and may be affected mainly by the tribo-chemical reaction in all the test conditions.     

Effect of Humidity on the Tribological Properties of Carbide-Derived Carbon (CDC) Films on Silicon Carbide

The effect of humidity on the tribological behavior of carbide-derived carbon (CDC) films prepared by high-temperature chlorination of silicon carbide was examined. Pin-on-disk tribological tests indicate that CDC, unlike graphite or glassy carbon, performs better in dry nitrogen (less than 0.05 friction coefficient at 0% humidity) than in humid air. This versatility is explained by the onion-like structure of the nanoporous CDC coating.     

Tribological behavior and graphitization of carbon nanotubes grown on 440C stainless steel

Vertically aligned carbon nanotube (CNT) arrays were directly grown onto 440C stainless steel substrates by plasma-enhanced chemical vapor deposition. Tribological properties of both short and long CNTs samples were studied under normal loads of 10 g, 25 g and 100 g. The CNTs had a steady-state friction coefficient of about 0.2 in humid air. In dry nitrogen, a friction of 0.2 was measured under a load of 10 g while high friction was measured at 25 g and 100 g loads. No significant variation of tribological behavior was measured between the short and long CNTs samples. SEM observations showed that rubbing caused the CNTs to align or lay down along the wear scar. They formed aggregates and were compressed by rubbing, which resulted in layer-structured graphite formations. SEM observation of the wear scars revealed loss of CNT structures accompanied by the appearance of dark areas. Micro Raman spectroscopic studies demonstrated that the dark areas were graphitized CNTs. Shear stress aligned the basal planes of the small graphene sheets in the CNT layers to the low friction orientation and eventually caused formation of more ordered graphite. The tribological formation of interfacial carbon layers increased with increasing stress from higher loads.     

W-C-S-Mo复合薄膜的制备及力学和摩擦学性能

利用磁控溅射与磁过滤阴极真空电弧（MS/FCVA）复合沉积法,在不同偏压下在单晶Si基体上制备W-C-S-Mo四元复合薄膜;分析沉积偏压对薄膜纳米硬度、弹性模量和膜基结合力等力学性能的影响;在潮湿大气、真空环境下研究偏压对薄膜摩擦学性能的影响。结果表明,薄膜硬度、弹性模量和附着力随着沉积负偏压的增大呈现先增大后减小的趋势,在偏压-100 V时薄膜力学性能最好;负偏压-100 V下制备的W-C-S-Mo四元复合薄膜样品在潮湿大气和真空环境下均具有较好的摩擦学性能,拉曼测试发现,W-C-S-Mo复合薄膜在潮湿大气环境中的润滑作用主要由DLC提供,而在真空环境中薄膜中的软质相MoS2晶粒起润滑作用。     

沉积气压对W-S-C复合薄膜结构和摩擦学性能的影响

采用磁控溅射方法制备W-S-C复合薄膜,研究沉积气压对薄膜结构和摩擦学性能的影响。结果表明,复合膜以非晶或纳米晶结构生长,沉积气压低时薄膜中C含量高,薄膜结构致密;沉积气压高时薄膜中WSx含量高,薄膜致密性下降。复合膜硬度在HV420～500之间,并且随着沉积气压的增加,硬度逐渐下降。在潮湿大气中的摩擦磨损实验表明,实验载荷越大摩擦因数越小;随着沉积气压的增加,复合膜的摩擦因数先降低后增加;当沉积气压在0.45～0.55 Pa时,复合膜的摩擦因数最低约为0.1,耐磨性能最好。     

沉积时间对MPTS自组装膜摩擦学性质的影响

利用分子自组装技术在羟基化后的单晶硅硅片表面制备(3-巯基丙基)三甲氧基硅烷(MPTS)自组装膜,用X射线光电子能谱仪(XPS)对薄膜的表面结构进行表征,用JGW-360a型接触角测量仪测量硅片表面的接触角,用UMT-200型微观摩擦磨损实验机测量硅片的摩擦因数,探讨沉积时间对自组装膜的摩擦学性能的影响。结果表明:MPTS自组装膜具有亲水疏水性能,其对水的接触角超过60°;硅片表面沉积MPTS可以大幅度降低硅片的摩擦因数,使硅基片表面的摩擦因数由无膜时的0.6降至0.25左右,且具有很好的耐磨性;沉积时间对硅表面自组装膜的摩擦学性能影响较大,在本实验条件下,0.5 h沉积时间所制备的MPTS-SAM硅片的耐磨性最佳,1 h沉积时间制得的硅片表面最为光滑。