Ti6Al4V表面增强CrN和TiN薄膜

目的 研究表面增强氮化铬(CrN)和氮化钛(TiN)薄膜与Ti6Al4V(TC4)基体的适应性。方法 采用热丝增强等离子体磁控溅射技术,通过改变热丝放电电流,在TC4合金表面制备CrN、TiN薄膜。采用扫描电子显微镜、X–射线衍射仪、纳米压痕仪、洛氏硬度计和摩擦磨损测试仪分别表征薄膜的组织形貌、成分、相结构、内应力、纳米硬度、弹性模量及耐磨性。结果 随着热丝放电电流从0 A增加至32 A,等离子体密度增大,薄膜表面形貌由较疏松的四棱锥形转变成致密球形,截面柱状晶排列更加致密;薄膜择优取向从低应变能的(111)取向转变为低表面能的(200)取向;无热丝放电时TiN薄膜内应力高于CrN薄膜,随着热丝放电电流的增大,TiN薄膜内应力逐渐低于CrN薄膜;并且随着热丝放电电流的增大,薄膜的弹性模量与硬度均增大,但相同试验条件下CrN薄膜的弹性模量与硬度均低于TiN薄膜;压痕检测结果表明,薄膜与基体结合完好;低载荷摩擦磨损检测结果表明,硬度及弹性模量较高的TiN薄膜磨损量最低。结论 在相同等离子体密度能量轰击下,硬度和弹性模量较高的TiN薄膜内应力增幅较小;低载荷磨损时,弹性模量及硬度较高、内应力较低的TiN薄膜更适用于Ti6Al4V基体的增强改性。     

自配对含氢类石墨碳薄膜超滑性能

采用等离子体增强化学气相沉积与原位渗氮复合技术在硅片和轴承钢球上制备了类石墨碳薄膜,将两者组成摩擦配伍对,并讨论自配对类石墨薄膜在氮气中摩擦学行为。利用往复摩擦机、扫描电子显微镜、三维表面轮廓仪考察自配对类石墨碳薄膜在不同载荷下摩擦磨损性能;采用高分辨透射电镜、拉曼光谱和红外吸收谱分析类石墨碳薄膜摩擦前后结构变化。摩擦测试结果表明：在载荷4 N时,薄膜摩擦因数为0.01;在8 N时,薄膜摩擦因数降低到0.005。这种变化归因于摩擦诱导薄膜结构进一步有序化以及沿滑动方向形成更加有序且更长石墨烯以及片状磨屑。证实了采用自配对碳薄膜方案是实现固体超滑一种有效途径。     

沉积温度对钢球表面含氢碳薄膜结构和摩擦学性能的影响

目前,含有类富勒烯碳结构的氢化碳薄膜(FL-C:H)主要通过等离子体增强化学气相沉积技术(PECVD)在单晶硅表面制备。文中在碳薄膜PECVD沉积工艺之前,通过额外引入原位渗氮方法在钢球表面沉积过渡层以增强薄膜与基材结合力,从而成功制备了具有类富勒烯结构的含氢碳薄膜。通过改变钢球表面碳膜沉积时间(30、60、90、120、150和180 min)获得厚度不同、结构变化的碳膜,进而研究碳膜的结构演变与摩擦学性能之间的关系。结果表明:FL-C:H薄膜PECVD沉积工艺(采用了比额外引入的原位渗氮工艺更低的基底偏压)使钢基底温度随沉积时间增加而下降,导致薄膜结构转变。碳膜结构最初为类石墨结构,随着沉积时间的增长逐渐转变为类富勒烯结构;沉积时间为180 min的碳基薄膜具有超低摩擦因数(0.009)和超长磨损寿命(53 000个周期)。     

铬掺杂碳基自润滑薄膜与铝合金的高温磨损机理

为了研究不同结构铬掺杂碳基薄膜在高温下与铝合金的磨损机理,采用非平衡磁控溅射在YT15刀具表面沉积Cr/CrC/DLC单周期和Cr/(CrC-DLC)_n多周期多层膜,在24、200和400℃下与A319和A390铝合金进行摩擦试验。采用扫描电子显微镜、原子力显微镜、纳米压痕仪、拉曼光谱仪、销盘磨损仪对薄膜的形貌结构、力学和摩擦学性能进行测试。研究表明:多周期多层膜结构打断薄膜柱状生长,提高膜基结合力。两种薄膜表面粗糙度和硬度分别为4.3 nm和5.4 nm、9.8 GPa和9.0 GPa。磨球表面转移层由硅、石墨以及剥落的薄膜碎片组成,连续的转移层降低摩擦因数;但随着温度升高,转移层的连续性被破坏,导致摩擦因数升高。在高温摩擦过程中,多周期多层膜磨损逐渐释放出DLC子膜层,通过DLC子膜层的石墨化转变来保持低摩擦因数,提高薄膜寿命。薄膜磨损由室温的磨料磨损转变为高温的粘着磨损和犁沟磨损,其中由于A390含有初晶硅使磨损以犁沟磨损为主。     

非晶碳基薄膜及其表面织构化后的水润滑性能研究进展

非晶碳基薄膜在水中具有低摩擦磨损特性和好的耐腐蚀性,但在摩擦过程中容易发生局部剥落,进一步提高薄膜在水中的承载力是目前的热点研究方向之一.在综合分析非晶碳基薄膜的摩擦学性能及其改性,以及采用表面织构化提高材料承载力的基础上,阐述了将两者相结合以改善薄膜整体性能的研究现状和发展前景.     

聚合物材料表面耐磨性能提升用非晶碳基薄膜的研究进展

硬度低、耐磨性能差等固有缺点已成为限制聚合物材料在一些苛刻环境中工业应用的重要因素。为了改善表面硬度和耐磨性能,多种表面改性技术被用于聚合物材料的耐磨防护,其中在聚合物材料表面制备一层非晶碳薄膜被认为可有效提高材料表面硬度和耐磨性能。综述了聚合物材料表面耐磨性能提升用非晶碳基薄膜的研究进展,分析了非晶碳基薄膜在聚合物材料表面膜基结合强度不足的本质原因,聚合物材料与非晶碳薄膜两种材料在结构和性质上的不匹配使两者之间的突变界面在载荷作用下极易发生失稳,造成了膜基结合强度的不足。探讨和对比了目前常用于改善非晶碳基薄膜在聚合物材料表面膜基结合强度的改性技术。其中,利用等离子体对聚合物材料表面进行处理,可以诱导材料表面有机碳质结构向无机碳质结构的逐渐转变,使非晶碳薄膜在聚合物材料表面获得可靠结合强度。利用等离子体处理法可以在聚合物基体表面构建原位转变层,原位转变层通过化学键的形式,为非晶碳薄膜在基体表面获得了可靠的膜基结合强度,有效提高了聚合物材料表面的硬度和减摩耐磨性能。     

橡胶表面碳基薄膜耐磨改性研究进展

橡胶具有良好的压缩性和回弹性及良好的气密性、耐溶剂性等性能,是航空航天、石油化工、汽车工业等领域必不可少的密封材料。然而,实际服役中其因摩擦因数极高(≥1)而易磨损失效,进而引发密封介质泄漏,严重影响设备安全性及服役寿命。类金刚石碳基薄膜由于其高硬度、化学惰性、低摩擦磨损特性等被认为是最有前景的橡胶表面耐磨改性涂层。一方面,通过调整薄膜沉积参数可以控制薄膜灵活度和沉积温度,足够的灵活度要求薄膜能够适应橡胶软基底形变而不会发生崩落,而低的沉积温度可以避免降解或破坏橡胶基底;另一方面,碳基薄膜的化学成分(主要包括碳和氢)与橡胶展现出极好的相容性,可以确保其良好的结合强度。综述了近20年来橡胶表面碳基薄膜耐磨改性研究的重要结果和最新进展,总结了目前研究中尚未解决的问题及未来的研究方向。     

碳离子注入医用Ti性能研究

采用等离子体浸没离子注入与沉积(PIIID)技术将碳离子注入Ti基体,研究碳离子注入对材料表面形貌、结构和组成的影响,评价改性材料的表面亲水性、荷电性、力学性能、耐腐蚀性以及细菌黏附能力和细胞相容性,探讨材料的结构和组成对其生物学性能的影响。结果表明,碳等离子体浸没离子注入与沉积(C-PIIID)技术处理的Ti基体表面主要由无定形碳组成。经碳离子注入改性,Ti表面形貌无明显变化,但其疏水性增加,表面负电性提升,表面力学性能和耐腐蚀性能得到提高。基体表面细胞的黏附、铺展和增殖情况良好,同时对大肠杆菌的黏附具有一定的抑制作用。     

磁控溅射沉积BC_x薄膜的摩擦学性能

探索具有优良摩擦学性能的BCx薄膜的制备方法具有重要意义,文中采用闭合场非平衡磁控溅射碳化硼靶和石墨靶(纯度均为99.9%)的方法,在38CrMoAl齿轮钢和Si(100)表面沉积BCx薄膜,利用场发射扫描电子显微镜(FESEM)、原子力显微镜(AFM)、拉曼光谱、纳米压入仪、CSM摩擦磨损试验机和X射线光电子能谱仪(XPS)分别分析了BCx薄膜的结构特征、力学性能和摩擦磨损性能,得到了石墨靶电流对碳化硼薄膜结构和性能的影响规律。结果表明:相同的沉积时间内,BCx薄膜的厚度随石墨靶电流的增加逐渐增大,硬度、弹性模量逐渐降低,微观形貌的柱状结构特征越来越明显;增加石墨靶电流可以提高BCx薄膜的摩擦学性能,当石墨靶电流为2.4A时,BCx薄膜的摩擦因数稳定在0.2左右,且具有最佳的耐磨性能。     

硅烷流量对钛合金双极板表面改性碳膜性能的影响

目的通过对钛合金基底进行表面改性,提高其作为质子交换膜燃料电池(PEMFC)金属双极板的耐蚀导电性能。方法通过等离子体增强化学气相沉积法(PECVD),调控不同的Si H4流量(0～10 mL/min),在钛基底表面制备了含硅非晶碳膜。利用电化学工作站、界面接触电阻测量仪、水接触角测量仪、纳米压痕仪,分别测试了薄膜的耐蚀性、导电性、疏水性和力学性能。通过拉曼光谱分析了腐蚀前后薄膜内部杂化比变化,并结合扫描电子显微镜和高分辨透射电子显微镜研究了薄膜厚度、腐蚀形貌和内部结构。结果 SiH4流量为8m L/min时,制备的含硅非晶碳膜具有最佳耐蚀性和导电性,该含硅非晶碳膜水接触角为102.91°,硬度为9.28 GPa,弹性模量为60.34 GPa,厚度为2.822μm。其动电位腐蚀电流密度为0.017μA/cm2,相比钛基底提升3个数量级(80.51μA/cm~2),在1.4 MPa压力下,其界面接触电阻为47.06 mΩ·cm~2。结论硅的引入诱导非晶碳膜生成类石墨烯结构,提高了非晶碳膜的导电性能和耐蚀性能,提升了薄膜的力学性能及疏水性。用含硅非晶碳膜对钛双极板进行表面改性,有望显著提高极板的燃料电池性能。     

类金刚石薄膜表面润湿调控研究综述

表面具有特殊润湿性特别是超疏水性的类金刚石薄膜,可满足在极端服役环境下(比如雨雪、潮湿环境中或者人体组织内)智能界面材料表面改性的需求.概述了类金刚石薄膜的生产工艺和性能优势及制备方法,介绍了具有特殊润湿性,特别是超疏水性的类金刚石薄膜的应用背景,同时提出了类金刚石薄膜表面润湿调控在理论和技术上的限制.在此基础上,阐述了类金刚石薄膜表面本征润湿性及与微观结构(包括杂化状态和短程或中程有序相团簇结构)间的关系.同时,基于经典的Wenzel和Cassie润湿理论,从表面化学组成和粗糙结构两个方面,重点论述了类金刚石薄膜表面润湿调控的方法及研究现状.通过等离子体表面处理、元素掺杂或者化学修饰改变DLC薄膜表面化学组成,实现DLC薄膜表面本征润湿改性.通过基体表面织构化或者薄膜表面形貌控制,构建DLC薄膜表面粗糙结构,控制界面润湿状态.二者共同作用可实现DLC薄膜表面润湿性在超亲水和超疏水之间变化.最后,总结并指出当前类金刚石薄膜表面润湿调控存在的一些关键科学问题,同时展望了未来的发展趋势.     

刻蚀工艺对四面体非晶碳膜生长及其性能的影响

目的研究不同等离子体刻蚀工艺对基体和四面体非晶碳膜(ta-C)的影响,并进一步考察不同电弧等离子体刻蚀时间对ta-C薄膜结构的影响。方法采用自主设计研制的45°单弯曲磁过滤阴极真空电弧镀膜设备,进行不同等离子体刻蚀以及ta-C薄膜的沉积。使用等离子体发射光谱仪表征离子种类及其密度,使用椭偏仪表征薄膜厚度,原子力显微镜表征刻蚀后的基体粗糙度,拉曼光谱仪和XPS表征薄膜结构,TEM分析薄膜的膜基界面结构。结果辉光刻蚀工艺中,作用的等离子体离子以低密度的Ar离子为主;而电弧刻蚀时,作用的等离子体离子为高密度的Ar离子和少量的C离子,并且能够在基体表面形成约15 nm的界面层,并实现非晶碳膜(a-C)的预沉积。随电弧等离子体刻蚀时间增加,ta-C薄膜的sp3含量有所降低。结论相比于辉光刻蚀,电弧刻蚀利于制备较厚的ta-C薄膜。这主要是因为电弧刻蚀时,基体表面形成良好的界面混合层,并预沉积了非晶碳膜,形成a-C/ta-C的梯度结构,有助于增强膜基结合力。     

A novel technique to enhance surface properties of DLC films deposited on the inner wall of cylindrical PET barrel by DC-RF hybrid discharge

A newly proposed technique has been utilized to improve surface properties of gas barriering DLC films deposited on PET bottle. The discharge in the bottle is induced by radio-frequency discharge and an external DC system is coupled to the RF power supply to control the potential of discharge electrode. In contrast to conventional discharge configuration, this leads to the capability to optimize the ion bombardment energy and surface properties of deposited films. The effect of negative DC voltage on the adhesion strength, optical transmittance, surface profile, roughness, and permeability of DLC coated PET samples has been investigated using immersion test, UV-visible spectroscopy, optical profilometry, and gas permeability tester, respectively. The results have demonstrated that the DLC coated PET samples with external bias show slight damage during beer immersion tests. Lower light transmittance is induced for the films deposited at high negative bias due to larger ion bombardment effect. There exists a proper bias to give rise to a small surface roughness. The gas permeability of DLC coated PET samples deposited with external bias has been substantially decreased compared to that of untreated one.     

Carbon tetrafluoride plasma modification of polyimide: A method of in-situ formed hydrophilic and hydrophobic surfaces

This study demonstrates that carbon tetrafluoride (CF₄) plasma can result in relatively hydrophobic and hydrophilic surfaces formed in-situ on polyimide (PI) films using a mask and controlling the distance of the mask to the substrate. The surface properties of plasma-treated PI films are characterized by contact angle measurement, atomic force microscopy (AFM), and X-ray photoelectron spectroscopy (XPS). Under specific modification conditions, contact angles for hydrophobic and hydrophilic surfaces reach values of 108.3 ± 0.6° and below 5°, respectively. The XPS analyses indicate that the “unshielded” surfaces contained a high proportion of the CF₂-CF₂ group and therefore decreased the wettability of the surface. On the other hand, the “shielded” surface contained hydrophilic groups such as carbonyl or carboxyl with few fluorinated groups, resulting in increased wettability of the surface.     

Chemical Structure of Carbon Nitride Films Prepared by MW-ECR Plasma Enhanced Magnetron Sputtering

SYNTHESIZE amorphous carbon nitride(hereafterreferred to as a-CNx)films was attempted even beforethe theoretical work by Liu and Cohen[1,2]whopredicted the possible existence of P-C3N4with bulkmodulus comparable to or even greater than that ofdiamond.Cuomo et al.were probably the first todeposit CNX films using radio frequency(RF)sputtering of carbon targets in nitrogen ambient[3].Han and Feldman obtained40percent nitrogen contentusing RF plasma in a mixture of methane and nitrogen[4]…     

The Electrical Characterization and NIR Absorption of ITO Film under Different Sputtering Time

Indium-tin-oxide(ITO)films with different sputtering time have been prepared by dc magnetron sputtering method on PET substrate at room temperature.The film structure,thickness,electrical and optical properties are investigated through XRD,SEM,van der Pauw method and FTIR,respectively.The XRD results indicate that all the films are amorphous structure.With the increase of sputtering time,resistivity and transmittance decrease simultaneously.However the absorption gets stronger,especially in near-infrared light region.Through Drude model the plasma frequency is calculated and the calculation result is pretty consistent with films deposited at 60 and 90 min.     

Study of the ageing behaviour of polymer films treated with a dielectric barrier discharge in air, helium and argon at medium pressure

Plasma treatment of polymers is gaining more and more popularity as a surface modification technique, since it offers numerous advantages over the conventional chemical processes. Plasma surface treatment is an environmentally benign, fast and versatile technology. However, it has one major disadvantage: the induced modification of the surface is not permanent, since the surface tends to recover to the untreated state. This ageing effect is due to the reorientation of induced polar chemical groups into the bulk of the material. In this paper, the ageing of polypropylene (PP) and polyethylene terephthalate (PET) films, treated with a dielectric barrier discharge operating at medium pressure (5.0 kPa) in air, helium and argon, is studied. This study is performed using contact angle measurements and X-ray photoelectron spectroscopy (XPS). Results show that the working gas used during plasma treatment has a significant influence on the ageing behaviour of both PP and PET films. The air-, helium- and argon-plasma treated PP films have a loss in treatment efficiency of 47%, 35% and 25% respectively, while the air-, helium- and argon-plasma treated PET films have a loss in treatment efficiency of 39%, 34% and 29% respectively. These results can be explained by the different cross-linking degrees of the polymer films after plasma treatment. Increasing the cross-linking degree will hinder the movement of the polymer chains and reduce the ageing effect.     

射频输入功率对类金刚石薄膜性能的影响

为了得到类金刚石薄膜的性质和制备参数之间的对应关系,利用射频等离子体增强化学气相淀积在单晶硅的(100)面上制备了类金刚石薄膜,反应气体是甲烷和氢气的混合气.研究了射频源的输入功率对类金刚石薄膜性能的影响.采用Raman光谱、X射线光电子能谱、原子力显微镜和纳米压痕仪对薄膜的微观结构、表面形貌、硬度和弹性模量进行了研究,结果表明:制备的薄膜具有典型的不定型碳的结构特征、薄膜致密均匀,随着入射功率的提高,薄膜的sp3含量、硬度以及弹性模量先增加后减小,并且在100W时达到最大值,在400W时薄膜出现碳化.     

Influence of twist and filament location in a yarn on effectiveness of atmospheric pressure plasma jet treatment of filament yarns

A twist free polyethylene terephthalate (PET) filament tow and ultrahigh modulus polyethylene (UHMPE) filament tows with 0, 1, 2, and 3 twist/cm are used as model systems to investigate the penetration of atmospheric pressure plasma jet modification effects through a single yarn. The change in surface wettability is determined using static contact angle measurements. Morphological and chemical changes on the fiber surface are characterized by scanning electron microscopy and X-ray photoelectron microscopy. The adhesion improvement is analyzed by micro-bond pullout test. For the PET filament tow, the fibers from the middle layer tend to have poorer treatment effect than those from the top and the bottom layers in terms of surface roughness, wettability and surface chemical composition change. For the UHMPE yarns, as the twist level increases, the plasma treatment is less effective in improving the fiber surface chemical composition, wettability and interfacial shear strength to epoxy due to the tightened yarn structure.     

类富勒烯/非晶多层碳膜的制备及性能

针对碳基薄膜存在的高应力问题,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制备了含氢类富勒烯/非晶层交替构成的类金刚石多层膜。采用高分辨透射电子显微镜和激光拉曼光谱仪分析了多层膜的结构特征;用X射线光电子能谱分析了薄膜的化学键状态;用纳米压痕仪测定了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了薄膜在大气下的摩擦学性能,同时比较了多层膜与非晶、类富勒烯薄膜的力学性能和摩擦磨损性能。结果表明:多层膜的硬度高于非晶和类富勒烯单层薄膜,达到28.78GPa;在大气环境下与Si3N4球对摩时平均摩擦因数略低于类富勒烯单层膜,耐磨性明显优于单层非晶和类富勒烯薄膜。