磨粒对齿轮箱磨损状态的影响

工程实践中迫切需要探究齿轮箱润滑油中磨屑的变化规律,从而实现对齿轮箱磨损状态的准确评价,进而系统性地揭示齿轮箱的失效机理。采用自主研制的齿轮箱磨损试验机进行摩擦试验探究,采用分散添加不同粒径铁磁性颗粒进入润滑油以及对纯净新油品中铁磁颗粒浓度规律进行跟踪监测的方法,结合对齿轮表面的形貌观测以及油样中的磨损颗粒的铁谱分析和磨损类型判断等技术方法,系统分析了齿轮箱的磨损失效机理。结果表明:磨粒的直径分布导致了不同的齿轮箱磨损失效机理,小尺寸颗粒易造成齿轮箱发生滑动磨损,而大尺寸磨粒主要引起齿轮箱发生疲劳磨损失效;工程应用中,润滑油铁磁颗粒浓度变化曲线的斜率达到tan50°时,齿轮表面发生轻微的点蚀磨损;浓度变化曲线斜率增至tan70°时,齿轮箱齿面已发生严重破坏,应做出预警处理。     

AFM研究表面活性剂对Fe2O3纳米薄膜形貌的影响

用ＦｅＣｌ３为起始原料水解法制备了Ｆｅ２Ｏ３纳米薄膜。实验中加入了不同的表面活性剂改善胶体与基片的附着力。使用原子力显微镜（ＡＦＭ）对簿膜的形貌进行了表征,讨率了表面活性剂影响簿膜中氧化铁纳米颗粒形貌的因素。     

基于NMM的AFM测试分析原子光刻纳米光栅样板

利用激光汇聚中性铬原子沉积出一维纳米光栅样板的基础上,基于 NMM的AFM测量系统对样板进行了测试分析和测试方法研究,得到一维纳米光栅结构平均节距为212.6±0 4nm,与52Cr原子共振跃迁(7S3→7P04)的半波长(λ/2)理论值212.8nm基本一致,测试结果非常准确.文章还介绍利用NMM测量机的大范围扫描测试距离,解决了光栅样板的测试区域快速定位的问题,对研究纳米级精度测量有实用价值及参考意义.     

用AFM探针诱导局域氧化工艺制备纳米样板的研究

本文介绍了纳米测量系统的组成和纳米样板的研究现状，讨论了AFM探针诱导局域氧化工艺的原理及其影响参数。用该方法进行了一维纳米结构样板的制备，并对实验结果进行了分析。     

Sialon陶瓷的冲蚀磨损及磨粒磨损行为

以ＳｉＣ作为磨粒较全面地研究了Ｓｉａｌｏｎ陶瓷的磨损性能：冲蚀磨损和磨粒磨损性能．Ｓｉａｌｏｎ陶瓷在冲蚀磨损实验中表现出了脆性冲蚀的特征,在高角冲蚀下,冲蚀磨损率随着冲蚀角度的增大而迅速增加,并在冲蚀角为９０°附近达到最大．ＳＥＭ分析表明Ｓｉａｌｏｎ陶瓷的冲蚀磨损机理主要是显微切削和表面颗粒拔出脱落．在Ｓｉａｌｏｎ陶瓷的磨粒磨损实验中,较高载荷作用下,磨损量与时间之间有指数变化关系;较低载荷作用下,磨损初期有一个短暂的磨损量基本不变的孕育阶段,随后进入快磨损阶段,本文对该孕育现象进行了探讨．对磨损表面的ＳＥＭ分析发现;Ｓｉａｌｏｎ陶瓷的磨粒磨损机理主要是犁耕和表面断裂脱落．     

基于AFM力曲线的纳米梁厚度的非破坏测量方法

本文阐述了基于原子力显微镜(AFM)的弯曲测试测量纳米梁厚度的理论和方法,并界定了基于AFM的厚度测量方法的适用条件,对基于AFM的厚度测量的两个典型应用进行了介绍.对硅纳米梁进行了厚度测量,并进行了重复性实验,梁的平均测量度为160.36nm.     

石墨纳米片/聚乙烯复合物分子动力学模拟

通过分子动力学模拟对石墨纳米片（GNP）/聚乙烯（PE）复合物的结构、力学和气体输运性质进行计算研究,分析其随模拟温度和GNP填充量的变化规律,探讨纳米界面形成、复合机制及结构与特性的关系。GNP/PE复合物呈现二维结构,GNP趋向于平面取向排列并通过范德华力和纳米石墨片层表面上的碳氢-π键使周围几个原子尺度内的PE分子固化为有序原子层,而PE基体仍然为各向同性的无定形结构。GNP/PE界面上纳米复合作用使体系能量降低,与PE体系相比,GNP/PE的杨氏模量和泊松比分别显著增高和降低。GNP平面取向导致GNP/PE的力学特性表现出二维各向异性的弹性常数张量,在石墨纳米片层平面方向上的杨氏模量明显增高,并且随温度的降低和GNP填充量的提高而增大,填充GNP有效改善了GNP/PE的力学性质。GNP/PE复合物的气体输运性质明显受到填充GNP的气体阻隔和取向的影响并且对3种气体渗透没有明显的选择性。GNP与基体的纳米复合导致N₂、O₂和CO₂的分子输运呈现二维各向异性,随着石墨纳米颗粒填充量的增加,取向GNP层面方向的扩散系数比垂直方向高5~8倍,可用于气体分子屏障与渗流控制。     

超高分子量聚乙烯磨粒磨损性能及机理的研究

本文利用ＭＬＳ－２３胶轮磨损试验机对超高分子量聚乙烯（ＵｌｔｒａＨｉｇｈＭｏｌｅｃｕｌａｒＷｅｉｇｈｔＰｏｌｙｅｔｈｙｌｅｎｅ）的磨粒磨损进行了研究，考察了磨损圈数（磨损时间）载荷对其耐磨性的影响，通过扫描电子显微镜（Ｓ６００）对其磨损表面形貌的观察，作者指出，超高分子量聚乙烯磨粒磨损的主要机理是犁耕和亚表层生断裂。     

AFM针尖耦合激光加工PMMA薄膜的加工重复性

利用飞秒激光与原子力显微镜的针尖部分耦合进行加工,是有望突破衍射极限,实现多隧道结加工的技术。本文在室温大气环境下,利用微焦级别脉宽为130fs、波长800nm的飞秒激光照射镀有金薄膜的原子力显微镜的探针针尖,使其耦合产生局域场加强效应在PMMA薄膜表面加工出光栅状纳米图形。通过最大残差法计算了条纹高度和宽度的重复性百分比,计算得到高度和宽度的最大残差值分别为6.3%和2.9%。结果表明在文中所提供的加工条件下,原子力显微镜针尖耦合激光是一种有潜力的激光加工方法。     

超高分子量聚乙烯磨粒磨损性能及机理的研究

本文利用ＭＬＳ－２３胶轮磨损试验机对超高分子量聚乙烯（ＵｌｔｒａＨｉｇｈＭｏｌｅｃｕｌａｒＷｅｉｇｈｔＰｏｌｙｅｔｈｙｌｅｎｅ）的磨粒磨损性能进行了研究。考察了磨损圈数（磨损时间）、载荷对其耐磨性的影响。通过扫描电子显微镜（Ｓ６００）对其磨损表面形貌的观察，作者指出：超高分子量聚乙烯磨粒磨损的主要机理是犁耕和亚表层脆性断裂。     

AFM Studies of Platinum Silicide Thin Films on Silicon Grown by Pulsed Laser Deposition

PtSi ultra-thin films were grown on Si-wafer using pulsed laser deposition(PLD).The surface structure of these films was studied by atomic force microscopy(AFM).In addition ,the compositional structure of the PtSi as deter-mined from X-ray photoelectron spectroscopy(XPS)is discussed.First report of a possible growth mechanism is presented, on studying the variation of morphological features(i,e,roughness and size of crystallites)with annealing temperatures and the film thicknesses..     

Porous Silicon： Volume-Specific Surface Area Determination from AFM Measurement Data

Porous silicon layers manufactured by using （100）, 1-5 ohm-cm p-type （boron doped） wafer by electrochemical etching in HF etanol solution. Photoluminescence （PL） spectra of anodically etched silicon obtained for different conditions studied and surface characteristics are investigated by AFM. This study gives a simple way to determine specific surface are of porous silicon which plays a major role with porosity for explaining the blue shift in photoluminescence peak. Properties such as specific surface area, pore size, and pore size distribution, the main surface properties of layer are investigated from AFM data which are important material characteristics in many processing applications. The ＂specific surface area＂ （Sspecific） generally defined as the area of solid surface per unit mass of material, solid volume or cross section area. From 3-D reconstructions of AFM data, the surface area and the volume of the porous layer can be estimated directly and volume-surface specific area is calculated. For porous silicon this feature can be defined as the total surface area per volume and given by the unit m2/cm3. The method is simple not need to construct a special set up for measurement and non destructive.     

淀粉及碘嵌入淀粉结构的原子力显微镜观测

采用原子力显微镜(AFM)对淀粉及碘嵌入淀粉的微观结构进行了观察与研究,结果发现,糊化淀粉分子间以水做媒介通过分子氢键的相互作用形成大分子量复合物,当浓度为0.16012 g/L时,淀粉分子间卷曲成螺旋型构象的表面较光滑单层超大分子。淀粉分子形成的超大分子在原子力显微镜下没有明显的空隙,小分子量的碘在分子间力的作用下能吸附在淀粉分子的表面,进而进一步嵌入到超大淀粉分子之中,螺距发生了非常明显的变化,由300 nm左右变成700nm左右,表面变得粗糙,形成了网状拓扑结构,网格的最大高度为5 nm。据估算每个螺距范围内有5×107个碘的复合分子嵌入淀粉分子中。     

An AFM/rotaxane molecular reading head for sequence-dependent DNA structures

DNA secondary structure may prove to be a significant obstacle both for enzymes that process DNA through an orifice and for the passage of DNA through nanopores proposed for some novel sequencing schemes. A nanomechanical molecular "tape reader" is assembled by threading a nanopore over DNA and pulling it using an atomic force microscope. Its formation is confirmed by studying the force required to open hairpins under that geometry. Unfolding induced by this 0.7-nm-diameter aperture requires 40 times more force than that reported for pulling on the ends of the DNA. Kinetic analysis shows that much less strain is required to destabilize the double helix in this geometry. Consequently, much more force is required to provide the free energy needed for opening.     

温度对PTCDA结构形貌影响的Raman和AFM分析

通过真空蒸发将PTCDA淀积在p-Si(100)面.采用Raman光谱,AFM分别研究了衬底温度对于PTCDA分子结构和表面形貌的影响,进而完善了p-Si基PTCDA薄膜的生长机制.     

ZTS晶体缺陷的实时AFM观测

利用原子力显微镜(AFM)对硫脲硫酸锌(ZTS)(100)面的生长过程进行实时观测研究,发现晶体表面凹陷及杂质对台阶推移的阻碍作用均有可能导致凹坑的出现;大台阶对凹坑和杂质的覆盖是包裹体产生的重要原因。首次观察到杂质分界点现象,不可移动杂质的存在不会终止台阶的推移。     

Metrology of semiconductor device structures by cross-sectional AFM

Atomic force microscopy (AFM) in air has been used to study various III–V semiconductor heterostructures. Topography of the (110) cleaved cross-sections has been examined where oxidation processes modify the surface and allow the structures to be investigated. It is shown that surface height differences of as little as 0.4 Å are sufficient to distinguish between layers, and that quantum wells of as little as 7 nm width are detectable.     

AFM Tip Hammering Nanolithography

Nanolithography at low cost and high speed is made possible by using a vibrating AFM tip in tapping‐mode as a nanohammer to forge polystyrene‐block‐poly(ethylene/butylenes)‐block‐polystyrene triblock copolymer monolayer thin films after annealing to transform their microstructures from as‐cast poorly ordered cylinders into well‐ordered hexagonal spheres. Annealing is accomplished in cyclohexane vapor, a selective solvent for the majority poly(ethylene/butylenes) block. Experimental results demonstrate that such structure‐tailored thin films enable macroscopic AFM tip writing to be performed in their surface; imprinted and embossed patterns can be generated with a sub‐20‐nm line‐width resolution. In addition, it is found that the lithographic patterns generated can be erased within 5 min by thermal annealing at 70 °C, and if necessary the erasion process can be expedited by increasing the annealing temperature.