传统油品添加剂对润滑脂中纳米粒子添加剂微动磨损性能的影响

考察了脲基脂中硫化铜纳米粒子添加剂与极压抗磨剂T203、T322、T301以及油性剂十八醇和十八酸共5种传统油品添加剂的微动磨损性能。结果表明：除T301外，其它几种油品添加剂与硫化铜纳米粒子添加剂存在协同作用，这种协同作用能进一步降低摩擦副的微动磨损体积。     

含纳米CaCO3,Cu混合物添加剂润滑油的研究

采用纳米碳酸钙、纳米铜粒子混合物作为润滑油添加剂.选择合适的表面活性剂制备含纳米碳酸钙和纳米铜粒子混合物添加剂的润滑油.利用四球摩擦磨损试验机考察含纳米碳酸钙、纳米铜粒子添加剂的润滑油的摩擦学性能;用扫描电子显微镜(SEM)观察表面磨痕的形貌.用原子力显微镜和扫描电子显微镜(SEM)观察分析在磨损表面纳米粒子的形态与分布.研究结果表明,纳米碳酸钙、纳米铜的粒子混合物的最佳添加量为:纳米碳酸钙与纳米铜的总添加量的质量分数为0.6%,纳米碳酸钙与纳米铜的质量分数之比为1∶1;该润滑油具有最佳的摩擦学性能.研究还表明,润滑油中纳米碳酸钙、纳米铜粒子混合物添加剂的优良摩擦学性能与纳米粒子在表面存在形态相关.     

纳米碳酸钙、铜粒子混合物用作润滑油添加剂的研究

本研究采用纳米碳酸钙和铜粒子混合物作为添加剂加入润滑油中,选择合适的表面活性剂制备含纳米碳酸钙和纳米铜粒子混合物添加剂的润滑油.采用四球摩擦磨损试验机测定含纳米碳酸钙、纳米铜粒子添加剂的润滑油的摩擦学性能;使用扫描电子显微镜(SEM)和能谱分析(EDS)等观察分析磨损钢球表面的磨痕形貌、化学元素和纳米粒子形态.结果表明,纳米碳酸钙、纳米铜的混合粒子的最佳添加量为:总添加量Wt(CaCO3 Cu)%=0.6%,WtCaCO3%:WtCu%=1:1;该润滑油具有最佳的抗磨、减摩性能.研究表明,含纳米碳酸钙、纳米铜粒子添加剂的润滑油的抗磨、减摩机理与纳米粒子存在形态相关.     

纳米硫代钼酸镍润滑添加剂的制备及性能

分别用微乳液反应法和乳状液相转移法合成了新型固体润滑兼油品添加剂-硫代钼酸镍纳米粒子.对它们的结构、形貌进行了分析观察,研究了用两种方法合成的纳米粒子在润滑油中的分散稳定性和摩擦学性能.用两种方法合成的硫代钼酸镍粒子大小均为十几纳米,用后一种方法合成的纳米粒子在润滑油中的分散稳定性更佳,润滑性能也更好.     

纳米润滑添加剂的摩擦学特性研究

纳米金属铜粒子粒度难以控制,其在润滑油中的分散性和稳定性也存在不少问题,为此,采用机械化学法在QM1SP04高能行星球磨机上制备出了铜颗粒粒径在15～60 nm之间的纳米铜浆,并与润滑基础油N68混合搅拌、沉淀后,获得了油溶性良好的纳米润滑油添加剂NT-1.用XP销-盘摩擦磨损试验机和四球摩擦试验机考察了NT-1添加剂的摩擦学性能,结果表明:添加NT-1纳米添加剂的N68润滑油比未添加时总磨损量减小了135%,出现了负磨损现象;将NT-1添加到长城15W/40SE汽油机油中,其PB值增加了26.0%,摩擦系数降低了11.1%,表现出良好的减摩性能和自修复功能.同时,将NT-1添加剂与3种有机钼盐配对试验,发现加入2%的硫化硫磷酸钼使基础油的承载能力提高了98.3%,其原因可能是有机钼与纳米铜之间存在协同作用.     

纳米硫化钼酸镍润滑添加剂的制备及性能

分别用微乳液反应法和乳状液相转移法合成了新型固体润滑兼油品添加剂-硫代钼酸镍纳米粒子。对它们的结构、形貌进行了分析观察,研究了用两种方法合成的纳米粒子在润滑油中的分散稳定性和摩擦学性能。用两种方法合成的硫代钼酸镍粒子大小均为十几纳米,用后一种方法合成的纳米粒子在润滑油中的分散稳定性更佳,润滑性能也更好。     

润滑油添加剂纳米氧化锌的制备、表征和应用

纳米微粒作为润滑油添加剂是开发高效无污染润滑油添加剂的新途径．以氧化锌作为添加剂，采用均匀沉淀和直接沉淀两种方法制备纳米氧化锌，并利用XRD和TEM对其进行了表征．将制备的ZnO纳米微粒有效改性后作为润滑油添加剂，在摩擦磨损试验机上对其摩擦学特性进行对比．研究表明，添加表面活性剂后，两种方法制备的ZnO纳米粒子效果不同，作为润滑油添加剂，纳米微粒团簇的分散和粒径变小，分散均匀，可起到有效的耐磨减摩作用。     

纳米粒子改善润滑油摩擦磨损性能的研究

利用MM200型磨损试验机研究了纳米粒子作为润滑油添加剂的摩擦磨损性能.实验结果表明:纳米粒子能明显地提高润滑油的抗磨减摩性能.并利用光学显微镜和扫描电子显微镜 (SEM) 观察了磨痕形貌,分析了纳米粒子在磨痕表面分别以"垫片"和"轴承"形式参与润滑.     

油溶性纳米铜对Al2024-GCr15钢摩擦副的摩擦学效应

将实验室合成的纳米Cu添加剂按质量分数1%加入到参比油中,使用SRV型微动摩擦磨损试验机考察了油溶性纳米铜添加剂对Al2024-GCr15钢摩擦副润滑过程中摩擦磨损行为的影响,并对摩擦副的磨损表面进行了分析.结果表明:油溶性纳米Cu添加剂有很好的抗磨减摩性能,能够明显地提高SJ15W/40汽油机油的品质,是一类比较优异的抗磨减摩添加剂.其抗磨减摩机理为软金属纳米颗粒(纳米Cu颗粒)在摩擦过程中由于物理、化学和电化学等的作用沉积到摩擦表面,在负载作用下铜、铝磨粒熔合、共晶重组并"焊接"在摩擦副上形成弥散分布的突起,从而起到抗磨减摩效果.     

环保型润滑油纳米添加剂的摩擦学行为

本文从环保的角度,选择并制备两种纳米材料（CaCO3、Cu粉）,作为润滑油抗磨、减摩的添加剂。介绍了两种纳米材料的水热法制备工艺,并进行了X射线衍射分析。将其通过超声波分散后,加入到20#润滑油中,利用MMS-2B摩擦磨损试验机进行摩擦学试验,测定合纳米粒子的润滑油的摩擦学性能。结果表明：可以采用水热法制备出高纯度的纳米级CaCO3粉、Cu粉;合纳米粒子的润滑油具有良好的抗磨减摩性能,滑动摩擦距离为400m时,其相对磨损量仅为0．13,摩擦系数为0．088。     

Estimation of Parameters of Universal Distribution of Moments of Failure of Products

A method is proposed for estimating the parameters of a mixture of exponential and Weibull distributions for which the accuracy of preliminary estimates obtained by graphical analysis is refined in accordance with the criterion of maximum likelihood. The efficiency of the proposed method is supported by the results of statistical modeling.     

Evaluation of optical properties of highly scattering media by moments of distributions of times of flight of photons

A novel method for the determination of the optical properties of tissue from time-domain measurements is presented. The data analysis is based on the evaluation of the first moment and the second centralized moment, i.e., the mean time of flight and the variance of the measured distribution of times of flight (DTOF) of photons injected by short (picosecond) laser pulses. Analytical expressions are derived for calculation of absorption and of reduced scattering coefficients from these moments by application of diffusion theory for infinite and semi-infinite homogeneous media. The proposed method was tested on experimental data obtained with phantoms, and results for absorption and reduced scattering coefficients obtained by the proposed method are compared with those obtained by fitting of the same data with analytical solutions of the diffusion equation. Furthermore, the accuracy of the moment analysis was investigated for a range of integration limits of the DTOF. The moment analysis may serve as a comparatively fast method for evaluating optical properties with sufficient accuracy and can be used, e.g., for on-line monitoring of optical properties of biological tissue.     

Analysis of the rate of propagation of the wave of change of boiling modes

An approximate analytical expression is derived for the velocity of the front of the wave of change of boiling modes on a rod and on a plate. The impact of the Thomson effect and of the heater orientation in the gravity field is included. Adequate agreement is demonstrated between the derived relations and experimental data.     

Estimation of potentialities of methods of summation of direct measurement errors

Conventional methods for summation of direct measurement errors are considered. Conditions under which these methods provide consistent results are stated. It is proposed to utilize for characteristic of the total error, its interval estimator or the half-sum of the value obtained by adding up its arithmetic and geometric random errors.Translated from Izmeritel'naya Tekhnika, No. 4, pp. 10–12, April, 1995.     

空压机轴承箱蜗壳温度探头油封改造

由于空压机进气侧轴承箱蜗壳温度探头密封效果不好,使空压机及其后续管道受到油污染。后将温度探头的O形圈密封改为骨架油封,杜绝了轴承箱漏油问题。文章简介空压机的结构和技术参数,详细介绍了骨架油封的制作和优点。     

Characteristics of mechanical properties of materials in studies of conditions of attainment of marginal states

It is shown that conditions of attainment of marginal states in the material of structural components are formulated on the basis of analysis of force and deformation criteria of formation and development of destruction. The parameters of these criteria are data on types of structural materials, standard and special characteristics of their mechanical properties, structural forms of considered elements of the equipment, and their operating stress loading. In this case, the construction of a system of state equations for describing interrelation of current damage, external actions, and responses to them is based on the concept of calculating variations in properties of materials at all stages of the design life cycle.     

Determination of parameters of microstructural inhomogeneity of deformation of metals by the method of modeling

The article suggests a method of evaluating the microstructural inhomogeneity of deformation of metals by modeling. The method includes the measurement of deformations of metal according to meshes of a dividing grid with small base and the calculation of the distribution parameters of microdeformations in model representation. It is shown that the modeling method makes it possible objectively to evaluate the microinhomogeneity of deformation of metals independently of the chosen mesh size of the dividing grid. New structural characteristics are introduced: the base and wave of variation expressing the degree of crumbling or amalgamation of metal grains by inhomogeneity of deformation.Translated from Problemy Prochnosti, No. 7, pp. 40–44, July, 1991.     

水三相点复现的不确定度评定

水三相点是开尔文热力学温度的唯一基准点，也是ITS-90国际温标重要的定义固定点。因此，水三相点不确定度分析对整个温标的建立、温度量值传递起着至关重要的作用。近3年来，中国计量科学研究院研制出一系列高质量的水三相点容器，加强了水三相点的研究，为不确定度的分析提供了更为可靠的实验依据。同时，不确定度的分析也是客观评价新研制容器性能的一个重要指标。因此，根据实验结果对新研制容器所复现的水三相点进行了不确定度评定。评定结果表明，其扩展不确定度为0．16mK(k=2．69，P=0．99)。