Influence of Pulsed Bias Voltage on Surface Properties of TiN Thin Films Deposited by Arc Ion Plating with Big Rectangle Shaped Targets

采用矩形平面大弧源离子镀技术在201奥氏体不锈钢基体表面制备TiN硬质薄膜, 研究了脉冲偏压对TiN膜层的表面形貌、相结构、硬度和耐磨性能的影响. 结果表明, 随着脉冲偏压的增大, 薄膜中大颗粒的数目先增加后减少, 这是大颗粒受到离子拖曳力和电场力双重作用的结果. 存在一个最佳的脉冲偏压, 使得制备出的TiN膜层具有较高的I(111)/I(200)比例和较高的耐磨性. 脉冲偏压为-300 V时制备的TiN膜层具有最好的综合性能.     

脉冲偏压幅值对TiN／TiAlN多层薄膜微观结构和性能的影响

采用电弧离子镀的方法,通过改变脉冲偏压幅值在M2高速钢表面制备了TiN／TiAlN多层薄膜,研究了脉冲电压幅值TiN／TiAlN多层薄膜微观结构和性能的变化。随着脉冲偏压幅值的增加,薄膜表面的大颗粒数目明显减少。EDX结果表明,脉冲偏压幅值的增加还引起Al／Ti原子比的降低。TiN／TiAlN多层薄膜主要以（111）晶...     

电弧离子镀中不同偏压模式对TiN薄膜形貌的黄美东

用扫描电子显微镜观察了电弧离子镀中各种不同偏压模式：不加偏压、加不同直流偏压和加幅值相同但占突比不同的脉冲偏压情况下获得的TiN薄膜的表面形貌,结果表明,脉冲偏压可以大大减小膜表面的大颗粒尺寸和数量,显著改善表面形貌。     

工艺参数对电弧离子镀沉积铜薄膜微结构及性能的影响

采用脉冲偏压电弧离子镀技术在不同工艺参数(弧电流、基体负偏压)水平下制备了一系列铜薄膜。利用金相显微镜、腐蚀失重试验和双向弯曲试验分别研究了弧电流和基体负偏压对铜薄膜组织结构、耐腐蚀性能和结合性能的影响。结果表明,弧电流由40A增加到80A,薄膜表面颗粒含量明显增加,大颗粒尺寸由13.71μm增加到19.36μm,膜层平均腐蚀速率降低;随着弧电流提高,薄膜结合性能先降低后提高,60A时膜层结合性能最理想;随着基体脉冲负偏压升高,薄膜结合性能提高,薄膜表面颗粒含量及其尺寸减小、负偏压达到200V时大颗粒净化效果明显;基体脉冲负偏压由20V升高到180V,膜层平均腐蚀速率先降低后升高,140V时膜层耐腐蚀性能最佳。     

脉冲偏压对磁过滤阴极电弧离子镀ta-C薄膜性能的影响

在不同脉冲偏压值下采用90°弯管磁过滤阴极电弧离子镀于硅片表面制备四面体非晶碳膜(Ta-C),研究了脉冲偏压对薄膜硬度、沉积速率、表面形貌及键价结构的影响。结论表明,薄膜沉积速率随脉冲偏压值的增加呈先增后减趋势,偏压值与膜层硬度值呈负相关性,高的偏压会抑制膜层中sp3键的形成,还能在一定程度上抑制大颗粒形成。本文研究内容为工业应用中通过脉冲偏压调整优化膜层综合性能提供参考。     

不同温度下氮化铬薄膜的疏水性能研究

利用电弧离子镀膜技术,以硅片、不锈钢、玻璃片为基底,在脉冲偏压分别为50 V、100 V、150 V的条件下制备了三组氮化铬薄膜样品,对其物相、表面形貌、力学性能及不同温度下的疏水性能进行了分析研究。结果表明：所制备薄膜样品组分单一,表面存在些许“大颗粒”,当脉冲偏压为100 V时“大颗粒”数量最多;氮化铬薄膜力学性能优良,150 V脉冲偏压下沉积的薄膜具有较高的硬度和杨氏模量,50 V脉冲偏压样品具有较高的膜基结合力;常温（20℃）下薄膜疏水性均较好,基底材料对疏水性能影响不大;各组薄膜疏水性能随环境温度的增加而降低,当环境温度上升至80℃时脉冲偏压为50 V的薄膜丧失疏水性能,脉冲偏压为100 V的薄膜样品疏水性能整体较优。     

反应溅射TiN纳米晶薄膜的结构特征和耐蚀性

利用直流反应溅射技术在不锈钢和硅基体上沉积了TiN纳米晶薄膜,采用场发射扫描电镜(FESEM)、X射线衍射(XRD)和电化学阻抗谱(EIS)技术研究了薄膜的表面形貌、相结构和耐蚀性与偏压的关系。结果表明,TiN薄膜的表面结构明显取决于所施加的偏压,适当提高偏压有利于获得细小、均匀、致密和光滑的膜层。XRD分析发现,TiN薄膜为面心立方结构,其择优取向为(111)面。实验显示,对应0V和-35V偏压的薄膜为欠化学计量比的,而偏压增加至-70V和-105V时的薄膜为化学计量比的TiN。EIS结果表明,较高偏压下的TiN薄膜几乎在整个频率范围内均表现为容抗特征,其阻抗模值明显高于低偏压下的膜层,这主要与较高偏压下的薄膜具有相对致密的微结构有关。较低偏压的TiN薄膜因结构缺陷较多其耐蚀性低于基体不锈钢。EIS所揭示的薄膜结构特征与FESEM观测结果一致。可见,减少穿膜针孔等结构缺陷有利于改善反应溅射TiN纳米晶薄膜耐蚀性。     

铝基复合材料表面多层复合厚膜的研究

对含50%AlN颗粒的铝基复合材料进行预处理后,在其表面依次采用浸锌化学镀镍工艺制备Ni-P过渡层,采用脉冲偏压磁过滤多弧离子镀工艺沉积硬质Ti/TiN调制周期膜,采用脉冲等离子体化学气相沉积工艺制备含氢类金刚石(DLC)膜等工艺最后形成了多层复合薄膜体系。利用X射线衍射仪、扫描电子显微镜、光谱仪、原子力显微镜、微载荷显微硬度仪、摩擦磨损试验机等设备分析了复合薄膜的组织结构、膜层形貌、截面形貌、显微硬度和摩擦系数等性能特点。测试表明:铝基复合材料/Ni-P层/Ti/TiN调制周期膜/含氢DLC膜这一梯度膜系具有结构交替变化,相邻界面形成混合层,性能梯度分布,硬度逐渐增加,摩擦系数小的特点。该复合工艺能够有效地解决铝基复合材料上制备硬质厚膜的热适配和晶格错配度大的难题,制备薄膜具有良好的膜基结合性能。     

纳米结构TiN薄膜的制备及其摩擦学性能

在室温条件下,用磁过滤等离子体装置在单晶硅基底上制备了纳米结构TiN薄膜分析了薄膜的表面形貌、晶体结构,测量了TiN薄膜的硬度,研究了基底偏压对薄膜结构性能的影响.结果表明,用此方法制备的TiN薄膜表面平整光滑,颗粒尺寸为50～80 nm;随着基底偏压的增大薄膜发生(111)面的择优取向随着偏压的提高,薄膜的颗粒度稍有增大,摩擦系数增大,偏压提高,晶面在较密排的(111)面有强烈的择优取向,硬度也有所增大.在其它条件相同的情况下载荷越大,摩擦系数越大.不起用磁过滤等离子体法制备的纳米结构TiN薄膜具有较低的摩擦系数(0.14～0.25).     

脉冲叠加直流偏压电弧离子镀TiCrNx薄膜的制备与性能研究

采用脉冲叠加直流偏压电弧离子镀技术在硬质合金刀具表面制备TiCrNx薄膜,利用XRD,SEM,多功能材料表面性能测试仪等对TiCrNx薄膜进行表征.结果表明,TiCrNx与TiN薄膜相比,硬度有所下降.膜-基结合力与靶材阴极弧电流及偏压有关.     

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)。