过滤电弧抑制薄膜中颗粒机理的实验分析

讨论利用直线型过滤电弧制备TiAlN薄膜中,过滤磁场作用于弧斑、靶中毒现象,电子和离子的回流和叠加偏压等因素影响作用的大小进行了实验分析.结果表明,磁场对弧斑分裂和弧斑运动速度的综合作用最为显著是由于直线型过滤电弧形成的瓶颈磁场造成的电子和离子的回流,以及直流叠加脉冲偏压形成的放电空间的等离子体磁撞,分解和离化的所起的共同作用的结果.这对于控制电弧离子镀沉积薄膜中的颗粒尺寸和颗粒密度,指定合理的工艺参数有一定的指导作用.     

电磁场对电弧离子镀沉积AlTiN涂层的影响

主要研究电磁场对电弧离子镀沉积AlTiN涂层的影响。通过改变电磁场的电压,研究阴极弧斑在不同电磁场下的运动现象以及AlTiN涂层的微观结构和力学性能。结果表明阴极弧斑的运动受磁场电压的影响。增加磁场电压,弧斑更多的在电弧靶中心区域聚集。AlTiN涂层的大颗粒分布、沉积速率、微观结构和硬度相应地受电磁场电压的影响。文章对相关机理进行了研究。     

阴极真空弧沉积中靶室第二阳极作用对系统性能的影响

介绍了阴极真空弧沉积中 ,弧源在阴极接地和阳极接地两种不同工作状态下的工作特性。发现阳极接地时 ,因沉积靶室入口法兰的第二阳极作用 ,聚焦磁场对弧源放电稳定性的影响不如阴极接地时明显。因此可以加较高的聚焦磁场 ,从而获得流强较高和较稳定的沉积等离子体束     

阴极真空弧沉积中靶室第二阳极作用对系统性能的影响

介绍了阴极真空弧沉积中，弧源在阴极接地和阳极接地两种不同工作状态下的工作特性。发现阳极接地时，因沉积靶室入口法兰的第二阳极作用，聚焦磁场对弧源放电稳定性的影响不如阴极接地时明显。因此可以加较高的聚焦磁场，从而获得流强较高和较稳定的沉积等离子体束。     

离子镀中弯管磁过滤器的效率和颗粒去除效果的研究

真空多弧离子镀沉积四面体非晶碳薄膜(ta-C)过程中,利用90°磁过滤器弯管去除大颗粒。本文探究了磁场强度、弯管偏压、弧电流和挡板孔径对弯管中离子传输效率(离子流)的影响,同时研究了薄膜表面颗粒去除情况。实验结果表明,弯管中离子流随磁场强度增强而增大,但增大磁场强度会导致颗粒数量增多;在中低磁场强度下,弯管偏压约为+15 V时可获得较高的离子传输效率,相比于不施加偏压提高了近70%;减小挡板孔径可使沉积速率降低,但可以显著改善大颗粒过滤效果;改变弧电流对弧源离子产生率和过滤器传输效率几乎没有影响,减小弧电流能够降低大颗粒的发射数量。本文研究内容为工业应用中采用磁过滤弯管减少薄膜大颗粒提供参考。     

电磁阴极磁场分布对磁控溅射系统伏安特性的影响

本文设计了一种新型圆形平面阴极磁控溅射源.该源具有独特的三极线圈结构,改变各线圈励磁电流可调节靶面磁场强度的大小和分布.通过对系统气体放电伏安特性随各线圈励磁电流大小变化规律的分析,以及对距靶面60mm基片台处等离子体束流密度大小和分布的测试,探讨了阴极磁场分布对磁控溅射系统伏安特性的影响.实验结果表明阴极磁场分布模式对气体放电稳定性和等离子体分布影响显著,当阴极磁场呈现收敛型分布时,二次电子被紧密束缚在靶面附近,降低了基片台附近等离子体束流密度,却增大等离子体束流径向分布均匀性.调节非平衡线圈励磁电流,在附加磁场的作用下,阴极磁场呈现发散型分布,二次电子被引向基片台附近,使得基片台附近等离子体束流密度显著增加但径向均匀性变差.     

旋转横向磁场对电弧离子镀弧斑运动的影响

研究了旋转横向磁场对电弧离子镀弧斑运动的影响规律,采用有限元分析软件FEMM对旋转横向磁场的分布进行了模拟,考察了不同频率(80~210 Hz)及电磁线圈励磁电流对弧斑运动的影响。从电弧斑点放电的物理机制出发,探讨了不同频率和磁场线圈电流对电弧离子镀弧斑运动的影响机制。结果表明,随着旋转横向磁场强度和频率的提高,使弧斑逐渐从聚集的斑点态(或者弱分散的团絮态)转变为大面积分布在靶面较强的分散弧斑絮线,最后转变为完全分布在整个靶面的强分散弧斑线,弧斑分裂强烈,产生的弧光等离子体更加均匀细腻。随着瞬态弧斑线在靶面分布面积的增加,弧压增加,弧电流密度急剧下降,靶材利用率达到85%以上。旋转横向磁场的应用,带来了弧斑大面积稳定放电、等离子离化率、密度及靶材利用率大幅度提高的多重效应。     

电弧离子镀的旋转横向磁场弧源设计

电弧离子镀工艺中电弧蒸发产生的大颗粒污染严重影响了所沉积涂层的性能.为了从源头上解决大颗粒难题,本文提出了一种新的旋转横向磁场的设计思路,通过频率和强度可调且覆盖整个靶面的旋转横向磁场控制弧斑的运动.通过有限元模拟磁场的分布,对旋转横向磁场控制的电弧离子镀弧源进行了优化设计.并根据方案制作了旋转磁场发生装置及其电源,使该弧源的旋转磁场具有多模式可调频调幅的功能,用以改善弧斑的放电形式,提高靶材刻蚀均匀性和靶材利用率,减少靶材大颗粒的发射,用以制备高质量的薄膜以及功能薄膜,以拓展电弧离子镀的应用范围.     

应用于工具镀膜的磁场辅助离子镀弧源及其放电特性分析

针对几种应用于工具镀膜的磁场控制的电弧离子镀弧源,分析了其结构、工作原理以及弧斑运动、放电特性;比较了不同磁场辅助受控弧源的靶结构及磁场位形,并讨论了对弧斑运动、放电及镀膜工艺的影响;对磁场控制的电弧离子镀弧源的发展进行了展望。     

阴极弧离子源磁过滤器的磁场设计与数值模拟

对于阴极弧离子源,磁过滤器的磁场设计是提高其性能的关键技术之一。针对现有磁过滤器对大颗粒过滤不足之处,本文利用永磁体优化磁过滤器的磁场位形,并且增大磁过滤器出口面积等方法,对弯管磁过滤器进行结构和磁场优化设计。由模拟结果可知:此过滤器具有弯管过滤、Bilek偏压、较大的出口面积、出口平面磁场强度大小均匀分布等优点。     

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.     

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.     

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.     

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)。