Cr及Cr-Ni掺杂对不同偏压下TiAlN薄膜性能的影响

为了使4Cr13不锈钢表面性能得到更好的优化和获得镀膜最佳的偏压工艺,在不同的偏压工艺下,采用多弧离子镀技术和磁控溅射技术在4Cr13不锈钢表面沉积掺杂Cr和同时掺杂Cr、Ni的TiAlN薄膜.采用附着力自动划痕仪研究不同偏压条件下薄膜与基体的结合力,采用扫描电子显微镜观察和分析薄膜的表面形貌,采用XRD技术检测薄膜的相结构,采用显微硬度计测量薄膜的显微硬度.结果表明:适当的偏压可以提高薄膜的硬度和结合力,在偏压为-250 V时,薄膜的表面硬度达到最大值2 259 HV0.1 N,结合力为36 N;并且掺杂Ni元素能够起到增强膜基结合力的效果.     

TiAlN和TiCrAlSiCN硬质薄膜微观结构与摩擦学性能研究

为改善H13钢的耐磨性能,本文采用工业型多弧离子镀设备在H13钢表面沉积耐磨硬质薄膜。借助扫描电子显微镜、X射线衍射仪、X射线光电子能谱仪、透射电子显微镜、维氏硬度计、摩擦磨损仪测试与分析TiAlN和TiCrAlSiCN薄膜的微观结构、硬度和摩擦学性能。低Al含量的TiAlN薄膜含面心立方结构的TiAlN固溶体和金属Ti相,TiAlN的200晶面呈择优取向;高Al含量的TiAlN薄膜为面心立方结构的TiAlN固溶体,111晶面呈择优取向。低Al含量的TiAlN薄膜硬度低(1871HV_(10 g))、高摩擦系数(0.8)和高磨损率(9.53×10~(-6)mm~3/N·m),高铝含量的TiAlN薄膜具有高硬度(3521 HV_(10 g))、摩擦系数明显下降(0.59)。TiAlN薄膜中加入Cr、Si和C元素形成的TiCrAlSiCN薄膜,其结构为纳米晶和非晶的复合结构,摩擦系数和磨损率降低是由于非晶相起减摩作用、纳米晶氮化物起耐磨作用;尤其低Si高C含量TiCrAlSiCN薄膜具有低摩擦系数(0.48)和磨损率(7.28×10~(-6)mm~3/(N·m)),高硬度(3613 HV_(10 g))。     

多弧离子镀TiAlN薄膜的制备及其抗氧化性能

目前,关于氮氩比对TiAlN薄膜高温抗氧化性能影响的研究较少。采用多弧离子镀技术在M2高速钢上沉积TiAlN薄膜,利用SEM、XRD等方法研究氮氩流量比对薄膜组织结构、表面形貌和抗氧化性的影响。结果表明:TiAlN薄膜呈δ-TiN面心立方晶体结构;随着氮氩流量比的提高,薄膜表面熔滴数量显著下降,膜层表面更加平整光滑,相结构的择优取向发生改变,硬度先增大后趋于稳定,表面氧化物含量逐渐下降;当氮氩流量比为9∶1时,所得TiAlN薄膜在800℃氧化温度下,其表面会生成一层致密的Al_2O_3保护膜,有效阻止了薄膜被进一步氧化,具有良好的抗氧化性能。     

磁控溅射制备TiAlCrN硬质薄膜及其抗腐蚀性能

采用反应磁控共溅射的方法,通过改变Cr靶溅射功率,在不锈钢基体上沉积不同Cr含量TiAlcrN薄膜.采用原子力显微镜(AFM)观察薄膜表面形貌;采用动电位极化试验研究薄膜的电化学腐蚀行为.结果表明:沉积的TiAlCrN薄膜表面平整、光滑、致密,无孔洞和突起等缺陷,晶粒细小,粗糙度低;TiAlcrN薄膜的抗腐蚀性好于不锈钢和TiAlN薄膜,且随Cr含量增加而增强.Cr含量为25.5%(原子分数)试样成膜质量最好,其抗腐蚀性约为不锈钢的15.0倍,约为TiAlN薄膜的7.7倍.     

4Cr13不锈钢表面镀TiN薄膜组织结构及性能的研究

采用多弧离子镀技术在4Cr13不锈钢上沉积TiN薄膜,在其他参数不变的条件下,研究不同弧电流下薄膜的组织、结构及性能。利用扫描电子显微镜、X射线衍射仪、显微硬度计、划痕仪和往复式摩擦磨损仪分别对薄膜进行表面形貌观察,物相分析,以及表面硬度、结合力、耐磨性检测。实验结果表明:弧电流对薄膜的表面形貌有明显的影响,随着弧电流的增大,薄膜表面的液滴数目和尺寸逐步增大;薄膜的相结构主要由TiN相组成,在(111)面有较强的择优取向,且随着弧电流的增大,衍射峰强度略有增加;随着弧电流的增大,薄膜的硬度先增大后减小,硬度值最大为2897HV;随着弧电流的增大,薄膜的结合力先增大后减小,当弧电流为105A时,薄膜的结合力最大,为75N;随着弧电流的增大,薄膜的摩擦系数先减小后增大,当弧电流为105A时,薄膜的耐磨性最好。     

直流磁控溅射制备(Ti,Al)N薄膜研究

本研究采用直流磁控溅射的方法在W 18Cr4V高速钢基体上制备不同Al/Ti比例的(Ti,Al)N薄膜,为此,在圆柱形磁控溅射Ti靶表面上,采用多弧离子镀技术覆盖不同面积和一定厚度的纯Al,结果表明:只有在靶材的外表面Ti与Al的交界附近的样品才能沉积成薄膜,随着靶材表面覆盖纯A l的面积增大,所形成的结晶薄膜中的Al/Ti比例增大,膜层中的相组成AlN的数量增多,而TiAlN的数量减少,此外纯Al的覆盖面积过大,将导致溅射时所需要的气压过高而无法沉积成膜。     

TiAlN和TiCrAlN薄膜的制备和耐磨性能

采用电弧离子镀和非平衡磁控溅射镀膜技术沉积TiAlN,TiCrAlN薄膜和TiCrAlN/TiCrN复合薄膜。采用扫描电镜(SEM)观察薄膜表面形貌和磨痕形貌,X射线衍射(XRD)检测薄膜结构,俄歇电子能谱仪(AES)分析薄膜成分,摩擦磨损试验评价薄膜的耐磨损性能。实验结果表明,采用Ti/TiN复合膜过渡层,可有效提高薄膜与基体的结合性能;采用磁控溅射与电弧离子镀复合技术制备的TiCrAlN/TiCrN薄膜表面较光滑、粗糙度小,与基体结合强度较高,仅产生较轻微的磨粒磨损和疲劳磨损,具有较优的耐磨性能,适合用于刀具表面处理。     

弧电流对多弧离子镀TiAlN涂层表面形貌和性能的影响

为优化TiAlN涂层的沉积参数,采用多弧离子镀技术在不同弧电流条件下于锆合金表面制备TiAlN涂层。利用扫描电子显微镜、能量色散X射线谱、高温热处理炉、划痕仪和X射线衍射仪分析弧电流对TiAlN涂层表面形貌、元素成分、高温抗氧化性、膜基结合力及物相结构的影响。结果表明:随着弧电流的升高,TiAlN涂层表面大颗粒数目逐渐增多,但涂层变得更加致密、孔隙率逐渐降低;弧电流为70 A时所制备的涂层高温抗氧化性能最好;膜基结合力随着弧电流的增加呈现出先增大后减小的趋势,弧电流为60 A时所制备的涂层膜基结合力最大,为32 N;弧电流为50 A时,涂层中物相Ti3AlN在(111)晶面、物相AlN在(100)晶面表现出择优取向。     

镍基合金基体上离子镀TiN薄膜的制备及性能

在镍基合金Inconel 740H基底上通过多弧离子镀制备Ti N薄膜.控制温度、气体流量、过渡层成分等重要参数,研究其对Ti N薄膜的表面形貌、力学性能以及耐腐蚀性的影响.多弧离子镀沉积过程中,沉积温度分别为200、250、300℃;过渡层成分分别为Al、Cr、Ti;气体流量分别为Ar 5 Sccm∶N240 Sccm,Ar 6 Sccm∶N248 Sccm,Ar 8 Sccm∶N264 Sccm.实验结果表明:在本实验的温度范围内,Ti N薄膜的致密度、结合力以及表面硬度均随着沉积温度的提高而提高;Cr作为过渡层的效果优于Al和Ti,薄膜成分均匀、表面致密,硬度更高,且耐腐蚀性能优异;在Ar、N2流量比一定的情况下,气体流量对Ti N薄膜的表面形貌和力学性能影响不大.本实验的最佳参数是:沉积温度300℃,过渡层成分为Cr,气体流量为Ar 6 Sccm、N248 Sccm.     

脉冲偏压对304不锈钢表面多弧离子镀CrAlN薄膜结构和耐蚀性能的影响

目前,鲜见有关脉冲偏压对多弧离子镀Cr Al N薄膜耐蚀性能影响的报道。以不同的脉冲偏压在304不锈钢表面多弧离子镀Cr Al N薄膜。采用扫描电镜、显微镜、X射线衍射仪、硬度仪、粗糙度仪分析了Cr Al N薄膜的表面形貌、相结构、硬度、表面粗糙度及耐蚀性能,分析了脉冲偏压对相关性能的影响。结果表明:随着脉冲偏压幅值的增大,Cr Al N薄膜表面大颗粒及凹坑尺寸和数量减少,薄膜质量提高;Cr Al N薄膜主要由(Cr,Al)N相组成,随着偏压增加,Cr Al N薄膜出现(220)择优取向;Cr Al N薄膜表面粗糙度随脉冲偏压增大而减小,显微硬度随脉冲偏压的增大而增大;Cr Al N薄膜在3.5%Na Cl溶液中的耐蚀性随着脉冲偏压的增大而增大,脉冲偏压为400 V时,Cr Al N薄膜与基体304不锈钢的腐蚀速率之比为0.34,薄膜的综合性能最好。     

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)。