用能谱技术确定基体薄涂层的厚度

提出一种不用标样确定基体薄涂层厚度并同时得到薄膜成分的新方法，通过理论计算，得出在不同涂层厚度下，涂层与基体的特征Ｘ射线相对强度比Ｉｃ／Ｉｓ，并作出理论曲线。然后用能谱技术测出Ｉｃ／Ｉｓ，可由理论曲线得出相应的涂层厚度，经实验证明该方法可行。用能谱技术确定基体薄涂层的厚度@冯显灿     

涂层材料的断裂分析

和基体厚度相比，涂层很薄，因此细观力学模型可把基体作为半无限弹性体，由于涂层和基体材料的膨胀系数及弹性系数不匹配，涂层材料中残余热应力的解析解为Ｅｃ／（１－ｙｃ）·（αｓ－αｃ）△Ｔ。用有限元法校核，该应力和解析解吻合得好，通过对涂层产生裂纹驱动力和断裂韧性的讨论，提出了抗裂涂层厚度公式。     

ISO/TC107“金属与其他无机覆盖层标准化技术委员会”简介

国标标准化组织第１０７技术委员会（ＩＳＯ／ＴＣ１０７）,名称为"金属与其他无机覆盖层（Ｍｅｔａｌｌｉｃ ａｎｄ ｏｔｈｅｒ ｉｎｏｒｇａｎｉｃｃｏａｔｉｎｇｓ）。它成立于 １９６２年,工作范围是;通过电解,熔敷,真空或化学沉积．机械沉积．离子镀等方式形成的保护性和装饰性金属覆盖层表征的标准化：通过电解,熔敷,真空和化学方式（不包括油漆和其他有机涂层）在金属表面形成的保护性和装饰性作金属覆盖层表征的标准化．这类覆盖的测试和检测方法的标准．沉积金属和其他无覆盖层前其基体准备的标准化。 ＩＳＯ／ＴＣＩ０７秘…     

基体性质对含涂层系统压痕响应的影响

对涂层/基体系统中,基体性质对涂层压痕力学行为的影响进行了研究,得出了基体对压痕载荷位移曲线的影响规律.研究表明:在给定的条件下,当压痕位移为涂层厚度的12%～16%时,由于基体屈服强度的变化,导致压痕载荷位移曲线在此处发生偏离;在压痕位移小于涂层厚度的10%时,不同的基体屈服强度得到的压痕响应完全一致,即基体的改变对压痕响应的影响是可以忽略的;同时还发现,在压痕位移为涂层厚度的30%时,如果基体屈服强度小于2000MPa时,基体屈服应力的改变会改变涂层的压痕力学行为,而当基体屈服强度大于2000MPa时,即使继续增大基体的屈服应力,所得到的载荷-位移曲线几乎重合,即其影响可以忽略.     

数码照相机的基础知识（下）

３２ＰＣ卡ＰＣ卡是按照图ＰＣＭＣＩＡ（ＰｅｒｓｏｎａｌｃｏｍｐｕｔｅｒＭｅｍｏｒｙＣａｒｄＩｎｔｅｎａｔｉｏｎａｌＡｓｓｏｃｉａｔｉｏｎ）的Ｉ／Ｆ标准的卡,根据厚度不同,有Ⅰ、Ⅱ、Ⅲ３种类型（在ＪＥＩＤＡ中第Ⅳ类也已标准化了）。ＰＣ卡按存取方法分为ＳＲＡＭ及ＲＯＭ等的存储卡和ＡＴＡ及ＳＣＳＩ等的Ｉ／Ｏ卡（图１３）。作为笔记本个人电脑之类的记录媒体使用的ＡＴＡ卡具有ＩＤＥＩ／Ｆ,有快闪存储器型及硬盘型。这种ＡＴＡ卡通常称为ＰＣ卡。因为ＰＣ卡用作数码照相机的媒体稍大些,所以目前仅用作专业照相机的…     

中华人民共和国国家标准容积真空泵性能测量方法

中华人民共和国国家标准容积真空泵性能测量方法ＭｅａｓｕｒｅｍｅｎｔＭｅｔｈｏｄｓｏｆＰｏｓｉｔｉｖｅ－ＤｉｓｐｌａｃｅｍｅｎｔＶａｃｕｕｍＰｕｍｐｓＰｅｒｆｏｒｍａｎｃｅＣｈａｒａｃｔｅｒｓｔｉｃｓ￥／／本标准参照采用国际标准ＩＳＯ１６０７／工一１９...     

金属／绝缘体／金属（Al／Al2O3／Au）隧道结的发光衰减机制

结合Ａｌ／Ａｏ２Ｏ３／Ａｕ结构的ＭＩＭ（ｍｅｔａｌ／ｉｎｓｕｌａｔｏｒ／ｍｅｔａｌ）隧道结Ｉ－Ｕ－特性、深度Ａｕｇｅｒ谱及结发光后结面透明度的测试与观察，对共发光衰减机制进行了研究。结果表明，由于ＭＩＭ结工作时，通过隧道电流等产生的大量焦耳上起底电极Ａｌ膜不断氧化，中间栅ＡＩ２Ｏ３的厚度不断增加，从而使得隧穿电子激发表面等离极化激元（ｓｕｒｆａｃｅ ｐｌａｓｍｏｎ ｐｏｌａｒｉｔｏｎ，ＳＰＰ）的强     

IEEE 488标准与GPIB-接口板的应用

ＡＮＳＩ／ＩＥＥＥ４８８标准是美国国家标准协会（ＡｍｅｒｉｃａｎＮａｔｉｏｎａｌＳｔａｎｄａｒｄｓＩｎｓｔｉｔｕｔｅ）与国际电工与电子工程师学会（ＩｎｓｔｉｔｕｔｅｏｆＥｌｅｃｔｒｉｃａｌａｎｄＥｌｅｃｔｒｏｎｉｃＥｎｇｉｎｅｅｒｓ）于１９８７年为计...     

海外文献速递

热　喷　涂20000601　汽轮机零部件涂层———ＨｏｗｍｅｔＣｏｒｐ.美国专利,5716726.(1998.2.10)汽轮机零部件(Ｎｉ基式Ｃｏ基合金)涂层组成为:(1)ＣＶＤ扩散铝化物层,该层外层区域为固溶金属化合物,靠近基体的内层扩散区间相由18%～26%Ａｌ(重量比,下同)、8%～35%Ｐｔ、50%～60%Ｎｉ组成,该中间相类似于Ａｌ+Ｎｉ、Ａｌ+Ｃｏ或Ａｌ+Ｐｔ金属间化合物,外层无固定相组成;(2)氧化铝层;(3)陶瓷热障涂层。20000602　低压激光喷涂合金———ＩｓｓｈｉｋｉＹ.Ｓｕｒｆａｃｅ＆ＣｏａｔｉｎｇｓＴｅｃｈｎｏｌｏｇｙ,1998,100～101(1～3):420(英…     

海外文献速递

金属腐蚀2 0 0 2 10 0 1　不同镍打底层对反应溅射沉积ＡｌＮ涂层腐蚀行为的影响———ＶａｃａｎｄｉｏＦ .Ｓｕｒｆａｃｅ＆ＣｏａｔｉｎｇｓＴｅｃｈｎｏｌｏｇｙ ,2 0 0 1,137(2～3) :2 84 (英文 )在钢基体上 ,用反应溅射方法沉积出具有耐蚀性能的氮化铝涂层。通过 0 .5ｍｏＬ/ＬＮａＣｌ溶液中的电化学感抗谱试验证明 ,具有较好的耐蚀性能 ,但随着在腐蚀液中浸入时间的延长 ,其耐蚀性明显减少。具有柱状组织的薄 (1μｍ)ＡｌＮ层中存在电解液进入钢基体的通道 ,为此必须在基体上覆盖阻挡涂层。探讨了由化学镀和电镀方法先在基体镀覆两…     

Instrument-invariant method of film thickness determination by means of substrate-to-film X-ray peak intensity ratioing

A simple method for the determination of thin film thickness using X-ray spectrometry is described. The ratio of the substrate X-ray peak intensity to that of the film is taken as a measure of the thickness of the film. A calibration curve, constructed using specimens of known thickness, can then be used for thockness determination. The results are independent of the incident electron beam current. The calibration curve is made instrument invariant by means of a normalization procedure and by taking into account the respective X-ray take-off angles. Normalized calibration curves are reported for 13 different elements on a silicon substrate, covering thicknesses between 2.5 and 650 nm. The method, ideally suited to thin films on solid substrates, can also be applied to films not on substrates, and in the presence of a thin organic interfacial layer between film and substrate.     

Spectral polarimetry technique as a complementary tool to ellipsometry of dielectric films

Ellipsometry is a highly sensitive optical technique for coating characterization but usually presents multiple solutions in many cases. To prevent these, a method with addition of a spectral polarimetric technique is proposed. An initial film dispersion curve, independently of its physical thickness, is then provided using the same setup as spectral ellipsometry and at the same sample position, which later is used for thickness determination and dispersion refinement with increase of reliability of results. Characterization of thin TiO2 films with one and two ellipsometric solutions is shown to corroborate the validity of the proposed method.     

On the factors affecting the critical indenter penetration for measurement of coating hardness

The nanoindentation test is the only viable approach to assess the properties of very thin coatings (<1 μm) since it can operate at the required scale and provides a fingerprint of the indentation response of the coating/substrate system. To measure the hardness of the coating only it is traditionally assumed that, as a rule-of-thumb, when the relative indentation depth (RID, i.e. the penetration divided by the coating thickness) is less than 0.1, the substrate will not affect the measured hardness of the coating. However, it is found that this rule is too strict for some and too loose for other coated systems. In this paper we present a comprehensive investigation of the factors influencing the critical relative indentation depth (CRID) using finite element simulation. The CRID is very sensitive to tip radius for soft coatings on hard substrates. For most coating/substrate combinations at reasonable penetration depths the 0.1 rule-of-thumb is a safe estimate. It is shown that the elastic property mismatch between coating and substrate also has an important effect on the measured hardness and this means that the Oliver and Pharr method generally used to extract hardness from nanoindentation data may give inaccurate results in coating/substrate systems with significant elastic mismatch.     

3-D Modeling of nanoindentation experiment on a coating-substrate system

The validity of indentation tests for the characterization of the mechanical properties of coatings relies greatly on the indentation depth. Deep indentation concludes to unreliable results due to the substrate effect on the measured properties. At shallow depths the size effect can also be an important error factor. The purpose of the present study is the determination of the critical ratio of coating thickness to indentation depth, up to which the substrate properties have a negligible effect on the force versus indentation depth curve and thus on determined mechanical properties of the coating. The analysis required, was conducted using finite element method. A spherical (ball) indenter was used and a three dimensional model of the indenter/coating-substrate system was applied. The effect of the coating to substrate Yield strength ratio, on the critical coating thickness to indentation depth ratio, was investigated for three different coating to substrate Young's modulus ratios. The results of this work provide considerable insight for the determination of the confidence indentation depth during micro-indentation for layered systems with different properties.     

Thickness measurement of nanoscale polymer layer on polymer substrates by attenuated total reflection infrared spectroscopy

For the first time, attenuated total reflection (ATR)-Fourier transform infrared (FT-IR) spectroscopy was utilized to measure the thickness (d0) of a nanoscale polymer layer on polymer substrate with significant credibility. First, a mathematical formula, A/A0 = 1 - 2d0/ d(p), was derived based on a self-defining subsection function (where d(p) was defined as depth of penetration of ATR and A and A0 were defined as the absorption band area of the characteristic functional group only contained in bulk substrate with a thin polymer layer attachment and the same group in blank substrate, respectively). On the mathematical model, through changing incidence angles, a series of values of A (A0) and corresponding d(p) were obtained, and when plotting A/A0 versus 2/d(p), d0 was obtained as the slope. With polystyrene (coating)/olypropylene (substrate) as a model system, we obtained the relevant values (d0). Comparing the results with the values of practical coating thickness (calculation and TEM observation), we found that this method was able to characterize well the thickness of a thin polymer layer on a polymer substrate in the range from 10 to 110 nm. Errors in the measurement were given and analyzed. Furthermore, this method was well applied in the thickness measurement of a polyacrylamide graft layer on a polypropylene film surface. The effect of pressure in the ATR technique on the coating thickness measurement was also discussed. In comparison with other methods such as XPS, SEM, TEM, and AFM, this approach based on a universal ATR technique was very convenient and fast. This method is expected to widen the application of the ATR-FT-IR technique and stimulate the further development of many fields such as surface self-assembly and surface functionlization.     

A new approach to the determination of optical constants and thickness of thin dielectric transparent films

A new calculating method to deduce optical constants n, k and thickness d from the fringe pattern of the transmission spectrum is proposed. In this method the optical parameters are determined using only one curve of the transmission spectra even for thin films where nd < /4. The method is demonstrated by experimental data obtained using evaporated vacuum deposited TiO₂ thin film on a glass substrate. The experimental values are in very good agreement with those calculated using the above described technique.     

Complete optical analysis of a non-absorbing thin film on an absorbing substrate by a new method of immersion spectroscopic reflectometry

A new method for determining the thickness and the spectral dependence of the refractive index characterizing a non-absorbing thin film placed on an absorbing substrate is described in this paper. Within this method two spectral dependences of the reflectance corresponding to the system immersed into two different non- absorbing ambients are employed. The main advantage of the method is that the values of the thickness and the refractive index can be determined by means of explicit formulae. The second important advantage is the fact that non-absorbing thin films with relatively small thicknesses can be analysed. The method is applied to amorphous SiO₂ thin films placed on silicon single-crystal wafers.     

Design of multilayer polymeric coatings for indentation resistance

Summary Indentation is often a mode of in-service loading for a thin coating deposited on a substrate. Under such a loading, the strong adherence of the coating to the substrate is a basic necessity for successful performance of the coating. In this study, we investigate the indentation behavior of thin single and multilayered polymeric coatings using the finite element method. The deformation patterns and the stress fields that are generated during indentation are obtained by employing constitutive models which accurately represent the elastic-viscoplastic and hyperelastic behavior of the glassy and rubbery states of the polymeric layers under investigation. Three types of loading conditions are considered: indentation to (1) a fixed depth; (2) a fixed work; and (3) a fixed force. For these loading conditions, we then investigate the mechanical performance of various composite coatings subjected to an overall thickness design constraint. The composite structure is altered via variation in individual layer material composition, layer thickness and layer arrangement. It is shown how the placement of different material layers in a multilayer coating can alter the flow pattern and hence the distribution of stress state and resulting failure. It is also shown that a soft rubber elastic layer acts to greatly minimize the interfacial shear stress at the substrate, thereby reducing the risk of delamination of the coating, but the presence of the rubber can also produce detrimental tensile stresses on the surface. We then demonstrate that the tensile stress state can be eliminated through manipulation of the rubber layer thickness, without increasing the interface shear stress. Through these examples, a framework for evaluation and design of multilayer coatings for indentation resistance is provided.     

Rapid inversion of eddy current data for conductivity and thickness of metal coatings

A feature-based method that determines the thickness and electrical conductivity of a coating on a metal plate from the change in the frequency-dependent impedance of an eddy-current probe coil is presented. Recently a least-squares solution of this problem was presented, which, however, requires approximately 20 CPU minutes on a DEC 5000 work station for the analysis of each set of measurements. We show that a feature-based approach can reduce the time to a few seconds on the same processor. We start by showing that a three-parameter scaling of the resistive component of the impedance change vs. frequency leads to a simple and nearly universal curve. Consequently these parameters provide a simple and compact way of expressing the data. Next, we show that the three scaling parameters can be used to construct a look-up table that determines the conductivity and thickness of the coating. Finally, we test the method using experimental data.     

近紫外冷反射镜的镀制研究

为充分利用紫外光源系统中所需要的有用的紫外光,同时减少红外光照射,根据常用紫外光源的发光特性、能量曲线分析,通过真空镀膜技术,在玻璃基片表面镀制多层硬质光学薄膜,制备出了对中紫外光谱区域的反射率高于90%,同时可见及红外区域的平均透过率在85%以上的近紫外冷反射镜。