原子吸收光谱法测定钛合金中铜含量的不确定度评定

根据航空工业部行业标准检验方法[1],结合实验室的日常分析实际情况,对原子吸收光谱法测定钛合金中微量铜含量进行不确定度评定。对测定过程中的标准曲线、样品称量以及使用仪器带来的不确定度进行了分析,并量化每个不确定度分量,并且确定最大不确定度分量为溶液浓度分量,从而合成标准不确定度以及形成该方法扩展不确定度的表达,为质量控制提供有效、可靠、可溯源的测量数据。     

光电直读光谱法测定纯铝中铁含量的测量不确定度评定

对采用光电直读光谱法测定纯铝中铁含量的测量不确定度来源进行了详细的分析,确定不确定度主要来源是标准物质标准值的不确定度、高低标校正产生的变动性、工作曲线的变动性、测量结果的重复性等,并对各测量不确定度的分量进行了评定,计算了其合成标准不确定度,最后给出了扩展不确定度。     

洗发液中有效物含量的测量不确定度评定

按照QB/T 1974-1994标准评定了检测洗发液中有效物含量的测量不确定度。从实验仪器、试剂、标准物质、操作及实验室环境等方面分析了不确定度的来源,对不确定度各分量进行分析、计算并进行合成。洗发液中有效物含量的测量不确定度主要来源于测量重复性和氯化物含量的测定。在试剂纯度、仪器设备的精度满足实验要求的情况下,有效物含量的相对扩展不确定度为0.12%。     

冷原子吸收分光光度法测定电子电气产品中汞的不确定度评定

根据《测量不确定度评定与表示指南》,对冷原子吸收分光光度法测定电子电气产品中汞含量的测量不确定度进行了评定。分析了影响不确定度的因素,对各不确定度分量进行了计算,结果表明测量不确定度主要来源于标准曲线拟合和测量重复性,合成相对标准不确定度为1.61%。     

芥子气纯度测定不确定度分析与评定

采用酸碱滴定法测定芥子气纯度,对测量结果的不确定度进行评定。分析了测定过程中不确定度来源,包括滴定剂的标定、消耗滴定剂体积、样品称量等引入的不确定度及其计算方法,最后合成得到标准不确定度。当芥子气纯度测定结果为94.78%时,扩展不确定度为0.34%(k=2)。实验结果表明,样品称量引入的不确定度对测量结果的影响最大。     

原子荧光法测定水中砷和硒的不确定度

对用氢化物发生原子荧光光谱法联合测定水中砷、硒的测量结果进行了不确定度评定。分析了测量不确定度的来源,如标准物质、样品取样体积、样品稀释体积、工作曲线的非线性及测量结果的重复性,对各不确定度分量进行了评定和计算。砷、硒含量测量的扩展不确定度均为5.28%。     

红外分光光度计检定不确定度评定

以JJF 1059.1–2012为依据,对红外分光光度计计量检定的不确定度进行评定。分析了检定过程中波数示值误差及透射比示值误差不确定度的重要来源,包括测量重复性、标准物质等引入的不确定度分量。对各不确定度分量进行分析计算,波数示值误差测量结果的扩展不确定度U=1.1 cm–1,k=3。透射比示值误差测量结果的相对扩展不确定度U rel=0.2%,k=2。     

火焰原子吸收光谱法测定齿科烤瓷修复用金基和钯基合金中银的不确定度评定

探讨了火焰原子吸收光谱法测定齿科烤瓷修复用金基和钯基合金中银的不确定度的评价方法。分析了不确定度的重要来源,包括称样质量、标准溶液的配制、工作曲线拟合、试液定容体积及测量重复性等引入的不确定度分量组成。对各不确定度分量进行分析计算,求得标准不确定度为0.023%,扩展不确定度为0.046%。     

高效液相色谱法测定水潺中苯甲酸含量的不确定度评定

立了高效液相色谱法测量水潺中苯甲酸含量的不确定度评定方案,合理地赋予被测量值的分散性。根据JJF1059—1999技术规范要求,以高效液相色谱法测定水潺中苯甲酸含量为例,分析测量过程中引起不确定度的各种因素,评估各不确定度分量,评定合成标准不确定度,包含因子取2（P=95%）,计算扩展不确定度,以不确定度的形式报告测量结果。方法的扩展相对不确定度为2.6%,本例样品测量扩展不确定度为0.022 g/kg,测量结果为0.866±0.022 g/kg。评定方案同时适用于高效液相色谱法测定食品中苯甲酸、山梨酸、     

大气采样器计量标准的测量不确定度

对大气采样器计量标准的测量不确定度来源如计量标准、流量示值误差、流量重复性、温度计示值误差进行了分析和评定,计算得合成标准不确定度和扩展不确定度分别为0.65%和1.30%.对测量不确定度的合理性进行了验证.     

Anodic film formation on binary Al?Mg and Al?Ti alloys in nitric acid

Nitric acid is commonly used for surface treatments of aluminium alloys. It is used to clean the surfaces after alkaline etching; it has application in chemical polishing and is also used for electrograining. The majority of these treatments undergo the application of anodic polarisation that results in formation of anodic oxide film. However, little is known about the behaviour of aluminium containing magnesium or titanium in solid solution under such conditions. To reveal the effects of magnesium and titanium alloying additions on anodic film formation in nitric acid, Al‐1800 ppm Mg and Al‐800 ppm Ti alloys were investigated. It was found that porous alumina film developed on the surfaces with reduced efficiency of 40%, due to the reactive nature of nitric acid to alumina. The presence of magnesium and titanium in aluminium had little influence on the efficiency of film growth, as confirmed by the relatively similar thicknesses of oxide formed on binary alloys and aluminium. However, incorporation of magnesium ions into the alumina film led to development of a high‐population density of localised voids near the alloy/film interface. An increased titanium content was found in the film regions close to the alloy/film interface, indicating its oxidation. Copyright © 2009 John Wiley & Sons, Ltd.     

Surface characteristics of titanium–silver alloys in artificial saliva

Titanium and its alloys are widely used in biomedical and dental fields because of their excellent corrosion resistance and biocompatibility. It is well known that titanium is protected from corrosion because of the stability of the passive film that controls and determines the corrosion resistance and biocompatibility of titanium and its alloys. The purpose of this study was to evaluate the electrochemical properties of titanium–silver alloys and the surface characteristics of passive film in artificial saliva. We designed titanium–silver alloys with silver contents ranging from 0 to 5 at.%, in 1% increments. These alloys were arc‐melted, homogenized, hot‐rolled to 2 mm thickness, and finally solution heat‐treated for 1 h and quenched. Potentiostatic testing was performed, and the open circuit potentials of the alloys were measured in artificial saliva, at 37 °C. The passive films of the titanium–silver alloys were analyzed via XPS. Titanium–silver alloys maintained low current density and showed stable passive region and also had high open circuit potential as compared with pure titanium. The open circuit potential of titanium–silver alloys increased as silver addition increased. With regard to the fraction of oxygen species, a component of over 80% was found to be comprised of oxide. Therefore, the titanium surface mainly consisted of titanium oxide and, on the titanium–silver alloys, this film was composed of TiO₂, Ti₂O₃, and TiO. As silver content increased, the TiO₂ fraction also increased, as did the thickness of the titanium oxide layer formed. Copyright © 2005 John Wiley & Sons, Ltd.     

Optimizing Strength and Ductility of Titanium Alloys by Oxygen: Review and Prospect

The traditional strengthening elements of titanium alloys include Al, Mo, V, etc., however, the high cost and toxicity of these elements put a limit on their further applications for biomaterials. Ubiquitous light elements such as oxygen are hopeful replacement due to high biocompatibility. It is recognized that the oxygen enhances the strength but pays the price of brittleness, thus the amount of oxygen is constrained. However, recent study results indicated that excess oxygen can keep high ductility together with high strength of titanium. This paper reviews the influence and the mechanism of oxygen on the strength and ductility of titanium alloys, and provides a new perspective for the strengthening method of titanium alloys.     

Ellipsometric Study of Anodic Oxide Films on Alloys of the Ti–Al System

Anodic oxide films (AOF) on neat titanium and on alloys of the Ti–Al system (Ti–10 at. % Al, Ti–24 at. % Al, Ti–50 at. % Al, Ti–75 at. % Al) formed in borate buffer solution are studied by ellipsometry. A model is proposed, which adequately describes the shape of the alloy surface with and without AOF. The model takes into account the roughness factor, allowing one to more correctly determine optical parameters of AOF and dependence of its thickness on anodic potential. It is found that the alloy surface roughness is effectively smoothed with increasing applied potential.     

ICP-AES法同时测定钛合金中多元素的研究

研究了应用全谱直读ICP-AES法同时测定钛合金中的铝、钼、铁、硅、钨、锡和锆.主要进行了多元素同时测定的分析线选定及干扰元素分析, 进行了酸度试验、回收率试验、精密度试验、内标元素等试验, 试验结果表明,方法快速、准确.     

Characterization of oxide layers on Ti6Al4V and titanium by streaming potential and streaming current measurements

Titanium and titanium alloys (e.g. Ti6Al4V) are increasingly used as medical implant materials in a wide variety of applications. So far, many surface properties of the passive layer considered to explain interactions with biological tissues are deduced from those of the crystalline phases of titanium dioxide (anatase, rutile, brookite), but do not necessarily correspond to those of naturally formed amorphous passive layers. We report on streaming potential and streaming current measurements on oxide layers on Ti6Al4V and Ti, carried out using a microslit electrokinetic set-up (MES) and a commercial electrokinetic analyzer (EKA, PAAR). Passive and anodic oxide layers on Ti6Al4V, as well as passive layers on titanium sputtered on glass, were investigated in this study. Isoelectric points (IEP) of ≈4.4 were found for all oxide layers. The IEP of the air-formed passive layer on Ti6Al4V did not depend on the KCl concentration. Hence, it was concluded that IEP is here identical to the point of zero charge (pzc). Controversially, the charge formation process seems to depend on the chloride ion concentration in the neutral and basic pH region.     

Electrochemical formation of cerium-containing oxide coatings on titanium

Possibility and conditions of obtaining cerium-containing oxide coatings on titanium alloys by microarc oxidation in electrolytes with tartrate and citrate cerium complexes were determined. The effect of organic cerium complexes on the kinetic parameters of the microarc oxidation of titanium alloys was studied. Porous oxides coatings containing up to 20% cerium were obtained.     

Effect of magnesium and titanium on the cathodic behaviour of aluminium in nitric acid

Cathodic polarization of aluminium and Al–0.18 wt.% Mg and Al–0.08 wt.% Ti alloys in 0.24 mol dm^?3 nitric acid solution at 38 °C has been employed to assist understanding of the roles of alloying elements in electrograining. The findings indicate that additions of magnesium and titanium to aluminium accelerate the corrosion of the substrate under the alkalization caused by the cathodic reactions. The accelerated dissolution and the consequent formation of hydrated alumina result in a decreased net cathodic current density in potentiostatic and potentiodynamic polarization conditions relative to the behaviour of aluminium. Copyright © 2014 John Wiley & Sons, Ltd.     

Universelles Verfahren zur Bestimmung des Aluminiums in natürlichen Materialien und technischen Produkten

The paper outlines what may be considered a universally applicable procedure for the determination of aluminium. It is based on a complexometric titration according to the NaF demasking technique employing voltametric indication. This is normally preceeded by chloroform extraction of elements which react with cupferron in strongly acidic solutions [e.g. Ti, Zr, Nb Fe(III), rare earth elements] and extraction of the aluminium itself (in the form of its cupferron complex) from acetic acid solution, chloroform again being employed as solvent, to effect separation from the alkaline earths. This latter extraction is necessary only where alkaline earths, in particular Ca, are present in excess of aluminium. Examples of application and detailed instructions are given for the determination of aluminium in rocks, limestone, iron ores, complex nickel basis alloys and titanium alloys. Although additions to the standard procedure may become necessary for certain sample compositions the standard process itself remains unchanged regarding the titration step. A high grade of accuracy (standard deviation of 0,03 for 10% of Al) and a wide range of application (0.005% of Al in limestone to 45% Al in Bauxite) are the advantages of the method proposed.     

Relationship between the Cu content and thermal properties of Al–Cu alloys for latent heat energy storage

Current Al alloys still have shortcomings in their volumetric latent heat (LHV), compatibility and high-temperature inoxidizability, which limit their applications in the field of latent heat energy storage (LHES). The performance of aluminum alloys can be improved by the addition of Cu. The effects of the Cu content on the phase change temperature, mass latent heat (LHM), LHV, supercooling degree and microstructure of Al–Cu alloys were first studied by means of power-compensated differential scanning calorimetry, density, composition analysis and metallographic analysis. The measured values of the latent heat of Al–Cu alloys have been compared with the theoretically predicted values. The results show that for Al–Cu alloys with 7.3–52.8% Cu, the melting/freezing temperature is 540–655 °C/510–637 °C; the LHM and the LHV are 290–340 J g^?1 and 877–1224 J cm^?3, respectively; and the degree of supercooling is within 10 °C. The LHM and LHV of Al–Cu alloys decrease with the increase in the Cu content; when the content of Cu is over 16.6%, the difference between the theoretical value of the LHM and the measured average of the Al–Cu alloys is within 5%. The LHES phases in Al–Cu alloys are the α-Al and theta phases. Quantitative relationships of the Cu content and metallurgical microstructure with the LHM and LHV of Al–Cu alloys are established, and both theoretical and empirical equations are obtained for the estimation of the latent heat for Al–Cu alloys.