纳米金刚石薄膜涂覆钛合金的摩擦学性能

医用钛合金(Ti6Al4V)具有低密度、高强度、耐腐蚀等优点而应用广泛,但是其耐磨性差.采用微波等离子体化学气相沉积法在医用钛合金上沉积金刚石薄膜,经喇曼光谱检测为纳米金刚石结构,原子力显微镜测试其晶粒尺寸为40 nm左右,表面粗糙度Ra=39 nm(视场10×10μm).在SiC球为摩擦副的干摩擦实验中,在2 N载荷下,摩擦因数在0.25左右,并且没有出现任何薄膜破裂或剥落现象.实验结果表明,钛合金表面沉积纳米金刚石薄膜后明显提高了耐磨性,薄膜的表面粗糙度和形貌是影响其摩擦学性能的关键因素.     

偏压对电弧离子镀CrNx薄膜结构和机械性能的影响

采用电弧离子镀技术在不锈钢基体表面制备了CrNx薄膜,并采用场发射扫描电镜、X射线衍射仪、显微硬度仪、球-盘式摩擦磨损试验机等手段对在不同偏压下沉积的CrNx薄膜的表面形貌、相结构、显微硬度和摩擦学性能进行考察.结果表明:随着偏压的增加, CrNx薄膜沉积率下降,厚度降低,CrNx薄膜表面颗粒逐渐变少,表面粗糙度降低,结晶度增大,晶粒尺寸增加;CrNx薄膜由Cr2N相和CrN相组成,薄膜的择优取向发生较大变化.当偏压为-100V时,CrNx薄膜的表面结构最致密,硬度最高,抗磨损性能最强.     

钢表面纳米TiAlN薄膜的结构表征与性能研究

目的在GCr15轴承钢和W18Cr4V高速钢基体上制备硬质耐磨的纳米TiAlN薄膜,以此来提高GCr15和W18Cr4V钢的使用寿命。方法采用直流反应磁控溅射的方法,以氩气为工作气体,氮气为反应气体,采用反复试验并优化后的一组参数,在两种常用的钢基体上制备高质量的耐磨薄膜。通过XRF、XRD、AFM和SEM研究了薄膜的元素含量、表面形貌和物相组成等结构特点,借助销盘式摩擦磨损试验机研究了薄膜的摩擦磨损性能。结果两组钢基体上薄膜的化学成分接近,Ti和Al元素的原子数分数之比为1:1,薄膜主要由AlN、TiN和TiAlN相组成,且在(111)方向具有择优生长取向,薄膜的平均晶粒尺寸分别为24.15 nm和28.32 nm;薄膜呈现岛状生长,表面的平均粗糙度为15.8 nm和17.6 nm,硬度值不足2500HV,摩擦系数分别为0.5和0.4,薄膜的磨损量分别为89μg和56μg。结论薄膜结构由硬质陶瓷相组成,平均晶粒尺寸较小,薄膜的摩擦系数稳定,磨损量较小,耐磨效果较好。     

Ru籽晶层对CoCrPt-SiO_2垂直记录层形貌及结构的影响

采用磁控溅射方法,制备了以不同厚度Ru薄膜为籽晶层的CoCrPt-SiO2垂直磁记录薄膜。利用原子力显微镜(AFM)、透射电镜(TEM)分析Ru薄膜的结构和形貌,并研究了其结构对CoCrPt-SiO2薄膜表面形貌、粗糙度及结构的影响。结果表明,CoCrPt-SiO2记录层的晶粒尺寸和粗糙度均随着Ru籽晶层厚度的增加而增加,薄而粗糙的籽晶层适合于高密度磁记录介质。对于CoCrPt-SiO2记录层晶粒的优化,厚度为70nm的Ru籽晶层有利于记录层薄膜晶粒的完全隔离,从而提高了磁记录性能。     

甲烷体积分数对纳米金刚石薄膜形貌的影响

目的研究不同甲烷体积分数对纳米金刚石(NCD)薄膜生长的影响,实现较小晶粒尺寸、高平整度的NCD薄膜的制备。方法采用微波等离子体增强化学气相沉积的方法制备NCD薄膜,以CH4/H2为气源,在生长阶段控制其他条件不变的前提下,探讨不同甲烷体积分数对NCD晶粒尺寸、表面形貌以及表面粗糙度的影响。采用SEM、XRD等观测NCD薄膜的表面形貌和晶粒尺寸大小,并利用Raman对NCD薄膜的不同散射峰进行分析。结果随着甲烷体积分数的增加,薄膜晶粒尺寸有减小的趋势。甲烷体积分数较低时,晶形比较完整,但致密度较小;甲烷体积分数较高时,晶形杂乱无章,但致密度较好。当甲烷体积分数为9%时NCD薄膜平均粒径达到最小,为21.3 nm,表面粗糙度较好,但非晶金刚石成分开始大量生成,NCD薄膜质量开始变差;当甲烷体积分数为8%时其形貌最好,且此时最小表面粗糙度小于20 nm。通过Raman分析可知NCD薄膜中出现了硅峰和石墨烯特征峰。结论甲烷体积分数对NCD薄膜形貌有较大影响,甲烷体积分数为8%时是表面平整度由较差变好再逐渐变差的分界点,且平均晶粒尺寸为23.6 nm,薄膜表面具有较好的平整度。     

纳米Pt膜的晶粒尺寸及其对热导率的影响

采用电子束-物理气相沉积法（EB-PVD）制备了6个厚度为15-62nm的铂薄膜,研究了纳米薄膜的晶粒尺寸及其对热导率的影响规律．当薄膜厚度小于30nm时,晶粒平均尺寸接近于薄膜的厚度;晶粒尺寸随着薄膜厚度的增加而增大并趋于定值;当薄膜厚度大于30nm时,晶粒尺寸约为20nm．受薄膜的表面和内部晶界的综合影响,铂纳米薄膜的热导率大大低于体材料的值,并且纳米薄膜的热导率随着薄膜厚度的增加而增大并趋于一个低于体材料热导率的值．     

橡胶表面粗糙度对DLC薄膜摩擦学性能的影响

目的 探究三元乙丙橡胶(EPDM)表面粗糙度对DLC薄膜和Cr/DLC的微观结构、附着力、摩擦学性能的影响,并阐明Cr中间层对橡胶表面DLC薄膜的作用。方法 使用砂纸打磨EPDM橡胶得到不同的表面粗糙度。采用非平衡磁控溅射技术在不同粗糙度的橡胶基体表面沉积无中间层的类金刚石碳基薄膜(DLC)及有Cr中间层的类金刚石碳基薄膜(Cr/DLC)。使用二维轮廓仪获得基体及薄膜的表面粗糙度,通过扫描电子显微镜以及拉曼光谱对薄膜的表面形貌和结构成分进行分析,并采用X切割试验和摩擦磨损试验分别评估DLC薄膜的附着力和摩擦学性能。结果 基体表面粗糙度对薄膜的微观结构没有显著影响,但却对薄膜附着力以及摩擦学性能有较大的影响。薄膜附着力随着基体粗糙度的增加呈现先增大后减小的趋势,当基体表面粗糙度为1 100 nm时,DLC薄膜具有最强的附着力和最佳的摩擦学性能。此外,Cr中间层的引入对提高薄膜附着力和承载能力起到了积极的作用。结论 适当增加基体表面粗糙度可以增强DLC薄膜的附着力,改善薄膜的摩擦学性能。Cr中间层可以提高薄膜的承载能力,从而提高薄膜的耐磨性。     

不同微观组织Ti靶对TiN薄膜微观结构和性能的影响

采用四种不同微观组织的钛靶,在同一沉积条件下在高速钢基底上磁控溅射得到氮化钛薄膜。研究了该四种氮化钛薄膜的表面形貌、表面粗糙度、表面颗粒、断口形貌、薄膜厚度、纳米硬度和相结构等。结果表明:随着等轴晶钛靶的晶粒尺寸的增大,氮化钛薄膜的表面粗糙度减小,表面颗粒尺寸、薄膜中氮含量、柱状晶尺寸、薄膜厚度、硬度均先变小后变大。魏氏组织钛靶沉积得到的氮化钛薄膜具有表面光滑、表面颗粒细小、柱状晶细小、硬度居中等特点。薄膜的硬度主要与薄膜中Ti N(111)的择优取向程度有关,择优取向度越高,硬度越高。     

沉积温度对NiCrAlY/Ag复合薄膜结构及性能的影响

目的改善GH4169合金的表面性能,制备摩擦学性能优良的复合薄膜。方法采用离子源辅助直流磁控溅射技术制备NiCrAlY/Ag复合薄膜,研究沉积温度分别为60、120、180℃对薄膜结构和性能的影响。利用能谱仪(EDS)、扫描电子显微镜(SEM)、原子力显微镜(AFM)、X射线衍射仪(XRD)进行薄膜元素成分含量、表面形貌、截面形貌、粗糙度和相结构的检测。采用纳米压痕仪、划痕法、球-盘式摩擦磨损试验机对薄膜的硬度、结合力、摩擦磨损性能进行分析。结果 NiCrAlY/Ag复合薄膜的表面致密度、晶粒尺寸以及表面粗糙度随沉积温度的升高而增大,物相组成主要为Ni3Al、Ag和Cr,薄膜的硬度在5.67～6.41GPa之间。复合薄膜的膜/基结合力随沉积温度的增加而降低,其中沉积温度为60℃时的膜基结合力最佳(33.1N),并且在此沉积温度下的复合薄膜具有最佳的室温摩擦学性能,其平均摩擦系数为0.24,磨损率为3.52×10–5 mm3/(N·m),磨损机制为氧化磨损和磨粒磨损。结论沉积温度对NiCrAlY/Ag复合薄膜的结构性能影响显著,当沉积温度为60℃时,薄膜综合性能最好。     

太阳能高反射薄膜制备技术对薄膜性能的影响

采用磁过滤阴极真空弧沉积(FCVAD)与磁控溅射(MS)两种技术在玻璃上制备厚度分别为75 nm和165 nm的Glass/Al高反射薄膜,利用Lambda 950分光光度计、扫描电子显微镜、原子力显微镜、附着力测试仪、摩擦试验机和加速老化试验箱分别表征薄膜的反射率、表面形貌、粗糙度、附着力、耐摩擦和耐老化性能,通过薄膜性能评估分析两种技术制备高反射膜性能的差异。结果表明:在双方优化工艺下,FCVAD制备的薄膜表面形貌和附着力优于MS薄膜;FCVAD制备的75 nm和165 nm薄膜反射率比同厚度MS薄膜高出3.3%~4.2%;75 nm厚的薄膜方均根粗糙度明显小于同厚度的MS薄膜;FCVAD制备的75 nm薄膜老化后反射率仅下降1.2%,而MS同厚度薄膜反射率下降了3.3%~4%。说明FCVAD在制备高反射膜方面比磁控溅射更有优势。     

Friction behaviour of diamond-like carbon films with varying mechanical properties

Diamond-like carbon (DLC) films deposited on silicon wafer with varying film thickness were investigated for their micro-scale friction behaviour. Films with three different thicknesses, namely 100 nm, 500 nm and 1000 nm, deposited by a radio frequency plasma-assisted chemical vapor deposition method on Si (100) wafer, were used as the test samples. The elastic modulus of the DLC samples increased with their film thickness. The micro-scale friction tests were conducted in a ball-on-flat type micro-tribotester, using soda lime glass balls with different radii (0.25 mm, 0.5 mm and 1 mm), and with varying applied normal load (load range: 1500 μN to 4800 μN). Results showed that the friction force increased with applied normal load, whereas with respect to the ball size, two different trends were observed. In the case of 100 nm thick sample, friction increased with the ball size at any given normal load, while for 500 nm and 1000 nm thick samples, friction had an inverse relation with the ball size at all applied normal loads. The friction behaviour in the case of the 100 nm thick film was adhesive in nature, whereas for the thicker films plowing was dominant. The friction behaviour of the test samples with the ball size, which was distinctly different, was discussed in terms of the contact area, influenced by their mechanical property, namely, the elastic modulus.     

Effects of substrate temperature and annealing on the anisotropic magnetoresistive property of NiFe films

Ni83Fei7 films with a thickness of about 100 ran were deposited on thermal oxidized silicon substrates at ambient temperature, 240, 350, and 410℃ by DC magnetron sputtering. The deposition rate was about 0.11 nm/s. The as-deposited films were annealed at 450, 550, and 650℃, respectively, in a vacuum lower than 3 x 10-3 Pa for 1 h. The Ni83Fei7 films mainly grow with a crystalline orientation of [111] in the direction of the film growth. With the annealing temperature increasing, the [111] orientation enhances. For films deposited at all four different temperatures, the significant improvement on anisotropic magnetoresistance occurs at the annealing temperature higher than 550℃. But for films deposited at ambient temperatures and 240 ℃, the anisotropic magnetoresistance can only rise to about 1% after 650 ℃ annealing. For films deposited at 350℃ and 410℃, the anisotropic magnetoresistance rises to about 3.8% after 650℃ annealing. The atomic force microscopy (AFM) observation shows a significant i     

Magnetic properties and structure of Ni80Fe20/Ni48Fe12Cr40 bilayer films deposited on SiO2/Si（100） by electron beam evaporation

Ni80Fe20/Ni48Fe12Cr40 bilayer films and Ni80Fe20 monolayer films were deposited at room temperature on SiO2/Si（100） substrates by electron beam evaporation. The influence of the thickness of the Ni48Fe12Cr40 underlayer on the structure, magnetization, and magnetoresistance of the Ni80Fe20/Ni48Fe12Cr40 bilayer film was investigated. The thickness of the Ni48Fe12Cr40 layer varied from about 1 nm to 18 nm while the Ni80Fe20 layer thickness was fixed at 45 nm. For the as-deposited bilayer films the introducing of the Ni48Fe12Cr40 underlayer promotes both the （111） texture and grain growth in the Ni80Fe20 layer. The Ni48Fe12Cr40 underlayer has no significant influence on the magnetic moment of the Ni80Fe20/Ni48Fe12Cr40 bilayer film. However, the coercivity of the bilayer film changes with the thickness of the Ni48Fe12Cr40 undedayer. The optimum thickness of the Ni48Fe12Cr40 underlayer for improving the anisotropic magnetoresistance effect of the Ni80Fe20/Ni48Fe12Cr40 bilayer film is about 5 nm. With a decrease in temperature from 300 K to 81 K, the anisotropic magnetoresistance ratio of the Ni80Fe20 （45 nm）/Ni48Fe12Cr40 （5 nm） bilayer film increases linearly from 2.1% to 4.8% compared with that of the Ni80Fe20 monolayer film from 1.7% to 4.0%.     

Stainless Steel Bipolar Plates Deposited with Multilayer Films for PEMFC Applications

A chromium nitride (CrN, Cr₂N)/chromium (Cr)/indium-tin-oxide (ITO) system and a gold (Au)/titanium (Ti) system were separately deposited using a sputtering method and an E-beam method, respectively, onto stainless steel 316 and 304 plates. The XRD patterns of the deposited stainless steel plates showed the crystalline phase of typical indium-tin oxide and of metallic phases, such as chromium, gold, and the metal substrate, as well as those of external chromium nitride films. The nitride films were composed of two metal nitride phases that consisted of CrN and Cr₂N compounds. The surface morphologies of the modified stainless steel bipolar plates were observed using atomic force microscopy and FE-SEM. The chromium nitride (CrN, Cr₂N)/chromium (Cr)/indium-tin-oxide (ITO) multilayer that was formed on the stainless steel plates had a surface microstructural morphology that consisted of fine columnar grains 10 nm in diameter and 60 nm in length. The external gold films that were formed on the stainless steel plates had a grain microstructure approximately 100 nm in diameter. The grain size of the external surface of the stainless steel plates with the gold (Au)/titanium (Ti) system increased with increasing gold film thickness. The electrical resistances and water contact angles of the stainless steel bipolar plates that were covered with the multilayer films were examined as a function of the thickness of the ITO film or of the external gold film. In the corrosion test, ICP-MS results indicated that the gold (Au)/titanium (Ti) films showed relatively excellent chemical stability after exposure to H₂SO₄ solution with pH 3 at 80 °C.     

Thickness Dependent Physical Properties of Thermally Evaporated Nanocrystalline CdSe Thin Films

This paper presents a study on thickness dependent physical properties of cadmium selenide thin films. The films of thickness 445, 631 and 810 nm were deposited employing thermal evaporation technique on glass and ITO-coated glass substrates followed by thermal annealing in air atmosphere at 200 °C. These films were subjected to X-ray diffractometer, UV–Vis spectrophotometer, scanning electron microscopy(SEM) and electrometer for structural, optical,surface morphological and electrical analysis respectively. The structural analysis reveals that the films are nanocrystalline in nature with cubic phase and preferred orientation(111). The crystallographic parameters such as lattice constant, interplanar spacing, grain size, internal strain, dislocation density, number of crystallites per unit area and texture coefficient are calculated and discussed. The optical band gap is found in the range 1.75–1.92 e V and observed to increase with thickness.The SEM study shows that the annealed films are uniform, fully covered and well defined. The electrical analysis shows that the conductivity is varied with film thickness and found within the order of semiconductor behavior.     

直流和高功率磁控溅射制备氮化铬薄膜及其结构性能比较

目的 比较直流磁控溅射（DCMS）和高功率磁控溅射（HiPIMS）两种沉积技术制备的氮化铬（CrN）薄膜的结构和性能。方法 采用DCMS和HiPIMS沉积技术,在金属镍（Ni）基底上沉积CrN薄膜,采用X射线衍射（XRD）、扫描电镜（SEM）和显微硬度计等仪器,分析CrN薄膜的晶相结构、表面以及截面形貌、基底与薄膜复合硬度、摩擦性能等。结果 XRD晶体测量显示DCMS制备的CrN薄膜在(111)晶面择优生长,内应力大;而HiPIMS制备的CrN薄膜为(200)晶面择优生长,内应力小。SEM显示两种方法制备的CrN薄膜都呈柱状晶体结构生长,但HiPIMS沉积的CrN薄膜颗粒尺寸较小,柱状晶体结构和晶粒更致密。硬度测量得到HiPIMS制备的CrN薄膜显微硬度为855.9HV,而DCMS制备的CrN薄膜显微硬度为501.5HV。此外,DCMS制备的CrN薄膜平均摩擦系数为0.640,而HiPIMS制备的CrN薄膜摩擦系数为0.545,耐磨性也好。HiPIMS制备的CrN薄膜的腐蚀电流比DCMS制备的CrN薄膜低1个数量级。结论 HiPIMS沉积技术制备的CrN薄膜颗粒尺寸小,结构更致密,且缺陷少、硬度高、防腐蚀性好,薄膜各项指标都优于DCMS沉积的CrN薄膜。     

Investigation of dry friction of submicrometer thick polyurethane films on a hard,smooth substrate

Our research on friction mechanisms has shown that the frictional force between sliding surfaces at moderate speeds and loads is primarily due to mechanical effects, such as plowing of surfaces by entrapped wear particles. In the absence of mechanical interactions, the coefficient of friction is extremely low. In this paper, one way of eliminating mechanical interactions is presented. Hard, smooth single crystal silicon wafers were dip coated in aqueous polyurethane dispersions. The film thickness was varied from 90 to 250 nm by diluting the elastomeric material with different amounts of water, yielding a mean surface roughness comparable with that of the substrate, i.e. 3 nm. Borosilicate glass balls, 4 mm in diameter, were used as the counterface. An ultra-low friction coefficient of 0.04 in dry sliding was achieved through an appropriate selection of film thickness and crosslinking density. The friction coefficient of such films is dependent on the normal load, exhibiting a minimum friction coefficient under a specific normal load. Higher loads result in tearing of the surface, whereas at low loads the viscoelastic losses of the surface layer contribute to the increase in the coefficient of friction. Under the optimal normal load and film thickness, there is no visible damage to the surface after the friction tests. However, atomic force microscopy of the tested surfaces revealed that, even when the friction coefficient was as low as 0.05, the surface of the films was plowed. In general, a higher friction coefficient corresponds to greater surface damage.     

溶胶-凝胶法制备Y2O3掺杂ZnO压敏薄膜及其电性能（英文）

研究溶胶-凝胶法制备不同浓度Y2O3掺杂对ZnO-Bi2O3压敏薄膜微观结构和电性能的影响。研究结果表明:Y2O3掺杂ZnO薄膜在750°C空气气氛下退火1h,ZnO薄膜的特征峰与ZnO的六方纤锌矿结构相匹配;ZnO晶粒直径随着掺杂量的增加而减小,Y2O3稀土掺杂氧化锌晶粒细化;薄膜厚度均匀且每一层厚度约80nm。研究结果还表明:当Y3+掺杂浓度为0.2%(摩尔分数)时,ZnO薄膜的非线性伏安特性最好,其漏电流为0.46mA,电位梯度为110V/mm,非线性系数为3.1。     

MPCVD纳米金刚石膜的微观结构及显微力学特性分析

利用微波等离子体化学气相沉积技术在光学玻璃衬底上制备了金刚石膜,利用原子力显微镜技术及显微力学探针研究了膜层的表面形貌及显微力学特性。结果表明,金刚石膜的晶粒尺寸小于１００ｎｍ,表面粗糙度小于１０ｎｍ,具有极高的显微硬度及弹性模量,能够满足光学材料表面的抗冲击,耐磨等要求。