Characterization and analysis of DLC films with different thickness deposited by RF magnetron PECVD

Diamond-like carbon (DLC) films have excellent mechanical and chemical properties similar to those of crystalline diamond giving them wide applications as protective coatings. So far, a variety of methods are employed to deposit DLC films. In this study, DLC films with different thicknesses were deposited on Si and glass substrates using RF magnetron PECVD method with C4H10 as carbon source. The bonding microstructure, surface morphology and tribological properties at different growing stages of the DLC films were tested. Raman spectra were deconvoluted into D peak at about 1370 cm-1 and G peak around 1590 cm-1, indicating typical features of the DLC films. A linear relationship between the film thickness and the deposition time was found, revealing that the required film thickness may be obtained by the appropriate tune of the deposition time. The concentration of sp3 and sp2 carbon atoms in the DLC films was measured by XPS spectra. As the films grew, the sp3 carbon atoms decreased while sp2 atoms increased. Surface morphology of the DLC films clearly showed that the films were composed of spherical carbon clusters, which tended to congregate as the deposition time increased. The friction coefficient of the films was very low and an increase was also found with the increase of film thickness corresponding to the results of XPS spectra. The scratch test proved that there was good bonding between the DLC films and the substrates.     

Use of diamond-like carbon with tungsten (W-DLC) films as biocompatible material

Diamond-like carbon (DLC), also known as amorphous hydrogenated carbon (a-C:H), are a class of materials with excellent mechanical, tribological and biological properties. When the DLC films are enhanced with other elements, all of these properties can be changed within a certain range.In this work, reactive magnetron sputtering was used to deposit W-DLC (hydrogenated tungsten carbide) films on Ti6Al4V (implant material). Many films were made using pure tungsten (99.99%) target and different plasmas processes, with different ratio among argon and methane. It was possible to change the films composition (from pure amorphous carbon to carbon enhanced with tungsten) according to ratio of argon and methane plasma. Between all films processed, the carbon films enhanced with tungsten showed good results in the “in vitro” cytotoxicity testing. Raman spectroscopy was used to analyze the chemical bonds kinds and the chemical bonds quantities. The Rutherford Back Scattering (RBS) was used to analyze the films compositions. The chemical inertness was analyzed by scanning voltametry. W-DLC thin films obtained in these processes have low roughness, high chemical resistance, good adhesion and show a high biocompatibility, when compared with common DLC thin films. Hence we have concluded that the tungsten concentrations in the DLC films make an important role to improve the properties of the DLC layers.     

316L不锈钢表面沉积类金刚石膜的拉曼光谱分析及润湿性研究

采用等离子体辅助化学气相沉积(PECVD)法,在316L不锈钢基体表面以不同的沉积气压和射频功率制备出类金刚石(DLC)薄膜.拉曼光谱分析结果表明:所沉积的DLC膜具有典型的类金刚石膜结构,薄膜中sp#键含量随工艺参数的不同而不同,射频功率100 W时,sp#键含量随沉积气压增高而降低.接触角测试结果表明:DLC膜沉积...     

DLC基纳米多层膜摩擦学性能的研究进展与展望

类金刚石（DLC）薄膜是一种良好的固体润滑剂,能够有效延长机械零件、工具的使用寿命。DLC基纳米多层薄膜的设计是耐磨薄膜领域的一项研究热点,薄膜中不同组分层具备不同的物理化学性能组合,能从多个角度（如高温、硬度、润滑）进行设计来提升薄膜力学性能、摩擦学性能以及耐腐蚀性能等。综述了DLC多层薄膜的设计目的与研究进展,以金属/DLC基纳米多层膜、金属氮化物/DLC基纳米多层膜、金属硫化物/DLC基纳米多层膜以及其他DLC基纳米多层膜为主,对早期研究成果及现在的研究方向进行了概述。介绍了以上几种DLC基纳米多层膜的现有设计思路（形成纳米晶/非晶复合结构、软/硬交替沉积,诱导转移膜形成,实现非公度接触）。随后对摩擦机理进行了分析总结：1）层与层间形成特殊过渡层,提高了结合力;2）软/硬的多层交替设计,可以抵抗应力松弛和裂纹偏转;3）高接触应力和催化作用下诱导DLC中的sp3向sp2转化,形成高度有序的转移膜,从而实现非公度接触。最后对DLC基纳米多层膜的未来发展进行了展望。     

常用碳基固体润滑薄膜的研究现状与展望

首先从碳基固体润滑薄膜的应用需求与成本效益出发,探讨了研究碳基固体润滑薄膜的迫切要求和重要意义,然后对类金刚石(DLC)薄膜、类富勒烯(FLC)薄膜及石墨烯薄膜三类最常用的碳基固体润滑薄膜的研究现状进行了较详细的介绍。其中,重点介绍了DLC薄膜的三种减摩抗磨机理,探讨了掺杂元素改性对DLC薄膜硬度、摩擦系数和磨损率等多个方面的影响,并指出外部因素(基体材料、过渡层和应用环境等)对DLC薄膜性能的重要作用。探讨了掺氢、掺氟和掺氮对FLC薄膜构性转变和摩擦学性能的影响。总体来说,氟掺杂导致FLC结构变化,并显著改变薄膜硬度;掺氮会诱导类富勒烯微结构的增加;掺氢FLC薄膜热处理后可达到超润滑状态。总结了石墨烯薄膜制备工艺的发展、石墨烯基复合薄膜的摩擦学性能和石墨烯薄膜在不同基体材料的应用。最后,指出了碳基润滑薄膜领域亟待解决的关键难题,并对未来的研究方向做出了预测。     

类金刚石薄膜的摩擦学特性研究进展

类金刚石薄膜(DLC)具有优良的摩擦磨损性能,但是DLC薄膜的摩擦学特性强烈依赖于制备技术、摩擦接触点的表面化学状态和物理状态,因此进一步提高类金刚石薄膜的摩擦学特性是目前的热门研究方向之一.在综合分析了近年来该领域研究的基础上,总结了影响DLC薄膜摩擦学性能的因素,并分析了各个因素的影响机理,以期找出一些规律为适应类...     

Zr掺杂类金刚石薄膜摩擦性能及耐腐蚀性能的影响

目的改善不锈钢摩擦性能及耐腐蚀性能。方法通过线性阳极层离子源辅助非平衡磁控溅射法,制备了不同Zr含量的类金刚石(DLC)薄膜,采用扫描电子显微镜、拉曼光谱仪、纳米硬度仪、高温销盘磨损仪、电化学工作站,对薄膜的化学成分、显微结构、纳米硬度、薄膜摩擦性能及耐腐蚀性能进行测试研究。结果随着Zr靶功率的增大,Zr含量线性增加。Zr含量从4.9%增加至16.3%时,I_D/I_G增大,薄膜硬度从12.1 GPa逐渐下降至8.4 GPa;Zr含量增大至21.2%时,I_D/I_G减小,薄膜硬度增大至11.4 GPa。涂镀类金刚石薄膜的不锈钢基体比无涂层的不锈钢基体有更低的摩擦系数,更好的耐磨损性能。Zr掺杂DLC薄膜的最小摩擦系数为0.07。Zr含量从4.9%增加至16.3%,DLC薄膜的耐腐蚀性能减弱;Zr含量继续增加,DLC薄膜的耐腐蚀性能增强。当Zr含量不大于11.9%时,沉积Zr掺杂DLC膜的不锈钢基体的耐腐蚀性能比不锈钢基体的更强。结论 Zr含量不大于11.9%时,Zr掺杂类金刚石薄膜既可以有效地改善不锈钢基体的摩擦磨损性能,又可以大幅提高耐腐蚀性能。     

Evaluation of diamond-like carbon films deposited on conductive glass from organic liquids using pulsed current

Hydrogenated diamond-like carbon (DLC) films were deposited on conductive glass substrates from methanol, DMF and acetonitrile by liquid deposition using a pulse-modulated source. The structure of the films was characterized by XPS, Raman and IR spectroscopy. XPS showed that the main constituent of the films was carbon. Raman and IR indicated that hydrogen was contained in the films and bonded preferentially to sp³ sites. From Raman spectra of the films, we found that DLC was formed in most experimental conditions and in some uncertain areas of the films deposited in DMF (1600 V) the diamond peak was also detected. The films had high transmission ratios (>70%) in the range of 330–2000 nm with VIS/UV spectroscopy. The resistivity of the films was of the order of 10¹⁰ Ω cm.     

Cr-doped DLC films in three mid-frequency dual-magnetron power modes

A series of Cr-doped diamond-like carbon (DLC) films were deposited using a mid-frequency dual-magnetron sputtering system, whose sputtering sources had three optional power modes of continuous DC, pulsed DC and AC (40 kHz). Morphology, microhardness, adhesion, and friction properties of the films were investigated using scanning electron microscopy, nano-indentation, scratch adhesion testing, ball-on-disc testing, etc. The results exhibited that the driving voltage waveforms played an important role in the properties of the films, and the properties of the films in pulsed DC mode were superior to those in AC mode and continuous DC mode.     

Composition and structure of Ti-C/DLC graded composite films

The Ti-C→DLC gradient composite films were characterized systematically.The elemental depth profile and elemental chemical state evolution were determined by X-ray photoelectron spectroscopy (XPS).The transmission electron microscope (TEM) and high-resolution transmission electron microscopy (HRTEM) were used to study the structure of interfacial zone between DLC film and Ti-C layers.Results show that there are composition transition zone between DLC film and either Ti-C layer or steel substrate on condition that pre-deposited Ti layers on the steel substrate then plasma based bias deposited DLC films.In Ti-C graded layer,the chemical state of titanium and carbon are changed gradually.The structures of zone in Ti-C layer near the DLC film is consisted of random oriented nanocrystallines TiC dispersed in amorphous DLC matrix.The structure of the zone between DLC film and Ti-C graded layer is gradually changed too.     

不同掺杂对类金刚石薄膜的影响

目的研究单掺Si和共掺Ag、Si对类金刚石薄膜的结构、摩擦学性能和耐腐蚀性能的影响。方法以高纯石墨靶、石墨与金属复合靶、Si靶作为靶材,采用射频增强磁控溅射技术制备不同掺杂种类的薄膜。通过XPS、拉曼光谱仪对薄膜的化学组成和结构进行分析,通过纳米压痕仪、摩擦磨损试验机、电化学工作站等,对薄膜的力学性能、摩擦学性能及耐腐蚀性能进行了系统研究。结果 Si元素单掺DLC会引起薄膜中sp~3C含量增加。Ag、Si共掺DLC后,由于Ag以金属相分布在薄膜中,并促进sp~2相的形成,导致sp~3C含量降低。掺杂元素后的DLC薄膜,硬度下降,但韧性提高,其中Ag、Si共掺的DLC薄膜的弹性恢复系数达到79%。此外,Ag、Si共掺DLC薄膜在多种气氛(Ar、O_2、N_2)中都具有优异的摩擦学性能,磨损寿命均超过30 min,其中在N_2气中的摩擦系数最低(0.1),并在NaCl溶液中的腐蚀电流密度比304不锈钢基体降低了近2个数量级,具有良好的耐腐蚀性。结论 Si与Ag共掺DLC薄膜较Si单掺薄膜具有更好的摩擦环境适应性和耐腐蚀性能。     

类金刚石膜超低摩擦行为的研究进展

近年来,高硬度、低摩擦、高耐磨性的类金刚石(Diamond like carbon,DLC)膜引起了国内外学术界和工业界极大的研究兴趣,尤其是它的超低摩擦行为。首先从宏观和微观角度分析了DLC膜超低摩擦的起源,研究发现DLC膜的微观结构和测试环境是影响DLC膜实现超低摩擦的主要因素,而DLC膜的微观结构由其制备工艺决定。然后系统讨论了制备工艺(包括制备方法、反应气源、掺杂元素和基体材料等)和测试环境(包括真空与干燥惰性气体环境、潮湿环境、高温环境、载荷和滑动速度等)对DLC膜超低摩擦行为的影响规律。最后归纳分析了目前对DLC膜超低摩擦机理的几种解释,指出DLC膜作为超低摩擦材料仍需解决的问题及未来的研究趋势。     

COMPARISON OF SURFACE PROPERTIES OF Ti-6Al-4V COATED WITH TITANIUM NITRIDE, TiN+TiC+Ti(C,N)/DLC, TiN/DLC AND TiC/DLC FILMS BY PLASMA-BASED ION IMPLANTATION

1. IlltroductionThe high yield strength and toughness, moderate modules, low density, good corrosionresistance and exceptional biocompatibility of Ti-6Al--4V alloy have made it increasinglypopular in industrial and medical application. But the alloy does not have enough wearresistance, and so is restricted in surface, particularly tribological applications to a certain e.tent[1--2]. It has been demonstrated that plasma-based ion implalltation (PBll), anew cost-effective technique for improvi…     

Tribological behaviors of hydrogenated diamond-like carbon films in different testing environments

Hydrogenated diamond-like carbon (DLC) films were deposited on Si substrate using plasma enhanced chemical vapor deposition(PECVD) technique with CH4 plus H2 as the feedstock. The tribological properties of the hydrogenated DLC films were measured on a ball-on-disk tribometer in different testing environments (humid air,dry air, dry O2, dry Ar and dry N2 ) sliding against Si3 N4 balls. The friction surfaces of the films and Si3 N4 balls were observed on a scanning electron microscope (SEM) and investigated by X-ray photoelectron spectroscopy (XPS). The results show that the tribological properties of the hydrogenated DLC films are strongly dependent on the testing environments. In dry Ar and dry N2 environments, the hydrogenated DLC films provide a superlow friction coefficient of about 0. 008 -0.01 and excellent wear resistance (wear life of above 56 km). In dry air and dry O2, the friction coefficient is increased to 0. 025 - 0.04 and the wear life is decreased to about 30 km. When sliding in moist air, the friction coefficient of the films is further increased to 0. 08 and the wear life is decreased to 10. 4 km. SEM and XPS analyses show that the tribological behaviors appear to rely on the transferred carbon-rich layer processes on the Si3 N4 balls and on the friction-induced oxidation of the films controlled by the nature of the testing environments.     

Deuterated Diamond Like Carbon films (DDLC): Mechanical properties in relation with microstructure

The aim of this work is to study the mechanical properties of Deuterated Diamond Like Carbon (DDLC) in comparison with Diamond Like Carbon (DLC), to clarify the influence of hydrogen in amorphous carbon thin film (a-C:H) of DLC type. For this purpose we substitute hydrogen (H) in the film by its isotope deuterium (D) by replacing CH₄ by CD₄ and their mixture 1:1 in the plasma. To investigate the deuterium role in the film structure, both hydrogenated and deuterated carbon films are deposited onto silicon wafer and glass substrates using a radio frequency PECVD device. All the amorphous carbon thin films are prepared with a negative self-bias voltage in the range of 50 V to 600 V. We obtain thus a wide variation of chemical composition. Single layer is produced with a constant thickness of 200 nm, controlled by X-ray reflectivity. The effects of deposition parameters on mechanical and adhesion properties of the DLC films are investigated using nano-hardness and nano-scratch tests. Chemical compositions are determined by ions and electrons spectroscopies (RBS, ERDA, XPS). We find, among other results, that replacing hydrogen by deuterium in amorphous carbon structure enhanced hardness properties for low self-bias voltage.     

淀粉包覆纳米银粒子的简易合成及其抗菌性能

采用直流磁控溅射技术,在n-Si (100)衬底上制备了CoxC100-x(x=2.5～50,at％)颗粒膜,并对薄膜的结构、形貌、磁性能和巨磁电阻(GMR)效应做了系统的研究.结果表明:制备态的Co-C薄膜为非晶结构,且表面光滑、颗粒尺寸及膜厚度均匀;随热处理温度的增加,Co成分在300℃逐渐开始晶化,400℃基本晶化完全,500℃度的时候膜层开始出现裂纹;拉曼光谱显示制备态薄膜为类金刚石(DLC)薄膜;X射线光电子能谱(XPS)分析表明,包埋在碳基薄膜中的Co掺杂纳米颗粒以单质形态存在,没有Co的碳化物出现,且Co掺杂没有促进碳膜的石墨化,Co-C纳米复合薄膜组成了一个互不相溶的金属/绝缘体体系;磁性能测试显示薄膜的饱和磁化强度(Ms)和矫顽力(Hc)与Co的含量和颗粒的晶化程度有密切关系;磁电阻测量结果表明Co2.5C97.5薄膜具有高达36％的正GMR效应,GMR效应遵循输运通道的转变机制.     

Electrodeposition of B,Ni co-doped diamond-like carbon films on AZ91D magnesium alloy: Corrosion and wear resistance

Diamond-like carbon (DLC) possesses brilliant and excellent properties, including excellent corrosion resistance as well as outstanding wear resistance. Ni and B co-doped DLC films were deposited on AZ91D magnesium alloy by electrodeposition under mild conditions (300 V and 25°C). Uniform and dense morphology of co-doped DLC films were observed, and Ni and B were uniformly incorporated into the carbon-based films. Among all the electrodeposits, the appearance of D and G peaks near 1330 and 1570 cm⁻¹ revealed that the as-deposited films were typical DLC films. As the addition of Ni was increased to 0.05 g, the highest microindentation hardness, the lowest friction coefficient, and wear loss were achieved to be 164.5 HV, 0.3, and 0.6 × 10⁻⁵ kg/m, respectively. The amorphous carbon films fabricated at 0.05 g Ni had the lowest corrosion current density and the most positive corrosion potential, which was mainly due to the small and dense granular structure effectively hindering the penetration of corrosion media.     

化学预处理对微型钻头沉积类金刚石薄膜附着力的影响

在刀具上沉积类金刚石(DLC)薄膜的关键技术问题是如何提高DLC薄膜的附着力,以发挥DLC薄膜在刀具涂层领域的优势。本文通过对微型钻头表面进行不同的化学预处理后利用射频等离子体化学气相沉法沉积DLC薄膜,对影响膜基附着力的内在规律进行了探讨。结果表明:采用简单酸碱腐蚀(先后使用NaOH溶液和HNO3溶液进行腐蚀)对DLC薄膜附着力的提高有一定作用,而综合腐蚀(首先使用酸碱腐蚀,然后使用Murakami试剂腐蚀)的效果更佳;此外,使用Murakami试剂腐蚀时间过长(超过6 min)会影响钻头本体的机械强度。实验结果对于DLC薄膜作为微型钻头涂层的应用具有很好的指导意义。     

Influence of carbon sputtering power on structure, corrosion resistance, adhesion strength and wear resistance of platinum/ruthenium/nitrogen doped diamond-like carbon thin films

Platinum/ruthenium/nitrogen doped diamond-like carbon (PtRuN-DLC) thin films were deposited on conductive p-Si substrates using a DC magnetron sputtering deposition system by varying carbon sputtering power. The chemical composition, bonding structure, surface morphology and adhesion strength of the PtRuN-DLC films were investigated using X-ray photoelectron spectroscopy (XPS), micro-Raman spectroscopy, atomic force microscopy (AFM), and micro-scratch test, respectively. The corrosion behavior of the PtRuN-DLC films in a 0.1 M NaCl solution was investigated using potentiodynamic polarization test. The corrosion results indicated that the corrosion resistance of the PtRuN-DLC films increased with increased carbon sputtering power probably due to decreased porosity level in the films with increased growth rate and film thickness. The wear performance of the PtRuN-DLC films was investigated with a ball-on-disc micro-tribometer. It was found that the increased carbon sputtering power significantly improved the wear performance of the films by enhancing the adhesion strength of the films.     

偏压类型对磁过滤等离子体制备优质类金刚石膜的影响

采用自行研制的磁过滤等离子体装置在单晶Si基底上制备了优质类金刚石(DLC)薄膜.运用红外光谱(IR)、扫描电镜(SEM),原子力显微镜(AFM)和纳米压痕仪对样品进行了表征和分析,着重研究了衬底偏压类型对制备薄膜的影响.结果表明:在无偏压或周期性负偏压下制备的DLC薄膜的sp3含量比连续负偏压下制备的薄膜的sp3含量要高;同时在周期性偏压下制备的薄膜表面较光滑,其表面粗糙度仅为0.1 nm,sp3含量达到66.8%,相应的纳米硬度也较高(达到80GPa).同时对相应的成膜机理进行了讨论.