镀锡板镀层的辉光放电光谱法解析

利用辉光放电光谱法对镀锡板样品进行逐层剥离,根据样品由表至里的辉光放电积分图谱,分别设定公式积分计算镀锡板镀层厚度及质量、钝化层厚度及质量、基板成分、镀层中有害元素等。采用辉光放电光谱对镀锡板做深度-时间图,可知镀锡层的深度分辨率低于基板铁层。将方法应用于测定镀层质量、钝化层质量、基板成分(碳、硅、锰、磷、硫、镍、铬和铜)的测定,相对标准偏差分别不大于2.3%(n=10)、3.0%(n=10)、4.3%(n=5),分别将实验方法测定结果与X射线荧光光谱法(XRF)、光度法、电感耦合等离子体原子发射光谱法(ICP-AES)进行比对,结果基本一致。采用实验方法对镀锡板镀层中的有害元素进行了测定,可实现镀锡板多个检测项目的同时测定。     

辉光放电质谱法测定高温合金中的痕量元素

研究了用辉光放电质谱法(GDMS)同时测定高温合金中的痕量元素.通过对分析元素同位素干扰情况的考察,对辉光放电参数如电流、电压、预溅射时间和积分时间的优化,建立了测定高温合金中B,P,Sc,Cu,Ga,Ge,As,Ag,In,Sn,Sb、Te,Hf,Tl,Pb和Bi共16种痕量元素的方法,该方法具有很好的准确度和精密度.     

Hydrogen permeation and diffusion in niobium

High temperature hydrogen permeation experiments were performed on niobium using ultra high vacuum techniques in an attempt to maintain clean specimen surfaces. Diffusivities and permeabilities were measured from 700 K to about 1400 K at hydrogen pressures ranging from 4.26 Pa to about 0.013 Pa. The measured diffusivities are in agreement with values extrapolated from the low temperature surface independent measurements. In contrast to low temperature measurements, a trend indicating a classical isotope effect is observed for hydrogen and deuterium diffusivities in niobium at the higher temperatures. The measured hydrogen permeation constants agree with independent solubility and diffusivity measurements and are characterized by a negative enthalpy, as expected from low temperature solubility and diffusivity measurements. These results are contrasted with previous measurements which appear to have been controlled by surface reactions.     

辉光放电质谱法测定钢铁和高温合金中钼

阐述了用辉光放电质谱法（GDMS）测定钢铁和高温合金中钼元素的方法。详细研究了金属的氩化物CrAr+、FeAr+和NiAr+对钼同位素测定的干扰影响。通过选择不受干扰同位素、利用同位素的丰度比例关系扣除和建立校准曲线扣除等方法对干扰进行校正。方法用于中低合金钢、不锈钢和高温合金标准样品的测定,测定值与认定值相符,表明了已成功地消除了氩化物CrAr+、FeAr+和NiAr+干扰对钼测定的影响,实现了钼含量的准确测定。     

辉光放电原子发射光谱法测定镀锌薄板中多元素

镀锌薄板基体成分分析是确保其材质的重要基础技术.在厂家建立校准曲线的基础上,通过对辉光放电原子发射光谱法测定过程中的一些影响因素(如:激发电压、激发电流、光谱描迹与漂移校正、取样质量、试样表面质量、氩气纯度与流量)进行控制,实现了对镀锌薄板中多元素的测定.按照实验方法对3块低合金钢标准物质进行测定,测定值与认定值基本一...     

Analysis of impurities in high-purity aluminum oxide by glow discharge mass spectrometry

A method has been developed for determining trace components in high-purity aluminum oxide powder for making sapphire single crystals. The analyses have been performed with VG9000 glow-discharge mass spectrometer which provided a sensitivity at the sub-ppm level. To analyze nonconducting specimens, a secondary cathode made of high-purity Ta foil was employed. Effects have been determined from factors that influence the sensitivity. Mathematical simulation has been used in calculating the effects of molecular ions on the results. Isotopes are identified that provide the necessary analysis sensitivity and accuracy. The method allows one to distinguish impurities adsorbed on the particles from those that enter into the crystal lattice.     

Hydrogen permeation in stationary arc-melted nickel 200

A combination of hydrogen permeation experiments and computer simulation was used to evaluate the distributions of temperature and of the hydrogen transfer flux in a stationary arcmelted Nickel 200 disc over the entire hydrogen permeation zone. The results indicate that the markedly nonuniform temperature distribution in the hydrogen permeation zone involves widely varying hydrogen fluxes and even transfer of hydrogen in different directions. At steady state, the hydrogen distribution is determined by a thermally produced dynamic equilibrium. Hydrogen supersaturation occurs in solid nickel at the solid/liquid interface in the arc-melted pool. An increase in hydrogen partial pressure in the shielding gas increases the heat input to the melt and decreases the stability of the arc melting process.     

Hydrogen trapping and permeation in nickel thoria

A series of modulated permeation experiments have been performed on foils of cold-worked nickel and nickel thoria (NITD). The parameters of the measurements include modulation frequency and base pressure together with the thickness, specimen temperature, and pretreatment of the foil. Experiments were carried out between 373 and 920 K. The frequency response of the permeation flux shows a characteristic form which has been modeled satisfactorily. Permeation and trapping data are derived from the fitting of the model to experimental characteristics. The degree of trapping dimin-ishes as the extent of the annealing increases, and as the base pressure (driving) increases, the degree of trapping decreases. These effects suggest that the trapping sites had been introduced by cold working, but that they are not directly associated with accumulation of hydrogen gas in the micro-voids. It is suggested that dislocation networks formed around thoria particles are responsible for the trapping of hydrogen in NITD with a depth of 40 kJ/mole. Trapping has also been detected for cold-worked nickel, at much lower temperatures than in NITD. Transmission electron microscopy (TEM) studies have also been correlated with measurements of hardness and resistivity to monitor the annealing process.     

玻尔兹曼分布研究辉光放电等离子体中铁原子谱线的激发机制

采用玻尔兹曼分布法,通过不同的放电参数,例如外加电压、电流和气压等,研究了辉光放电等离子体中激发能量为4.1～7.0 eV的铁原子谱线激发机制。低激发能量曲线很好地拟合了正玻尔兹曼分布,然而较高激发能量的原子谱线与线性玻尔兹曼曲线有很大偏差。其结果可能是由于较低等级激发由热碰撞引起,而另一方面,铁原子高位等级的激发则是铁原子和氩或氖亚稳原子间的碰撞引起的。     

The application of a glow discharge mass spectrometer in the steel industry

With the VG 9000 glow discharge mass spectrometer (GDMS), major, minor, and trace elemental constituents in conducting and semiconducting materials can be measured directly. The instrument has been developed by a combination of two well founded and proven techniques; namely, a glow discharge cell for the production of ions and a double focussing mass spectrometer designed for high resolution and high sensitivity. The glow discharge cell offers the advantage that the sputtering action and the subsequent ionisation which occur, lead to minimal matrix dependency and a narrow range of sensitivity factors across the entire periodic table. The VG 9000 GDMS has been sucessfully employed to analyse a wide range of materials including steel. For most elements the detection limits are in the ppb range. Carbon, nitrogen and oxygen have been analysed successfully to ppm concentration levels. The glow discharge mass spectrometry has considerable potential for the steel industry, offering a high level of precision together with high speed of operation.     

Hydrogen permeation and diffusion in iron-base superalloys

In this work, the hydrogen permeation and diffusion in three iron-base superalloys, JBK-75, Incoloy903 and GH35A, were investigated. A gaseous permeation technique was employed to measure the hydrogen permeabilities and diffusivities of specimens with different, heat treatments for a given alloy over the temperature range of 210–430°C. The effects of strengthening phase γ′ on the hydrogen permeation and diffusion in the alloys were examined. The results showed that the dependences of the hydrogen permeabilities and diffusivities in various alloys on the temperature obeyed Arrhenius relationship over the test temperature range and that the hydrogen permeation behavior in these alloys was essentially independent of their heat-treated conditions, i.e. which was not significantly affected by γt́ precipitates in the alloys. The hydrogen permeation parameters of the iron-base superalloys were approximately consistent with those of the austenitic stainless steels. The hydrogen transport in these alloys with f.c.c. structure was generally controlled only by the lattice diffusion of hydrogen.     

高温合金中多元素辉光放电质谱法测定及干扰校正

通过辉光放电质谱法(GDMS)测定了高温合金中的C,Mg,Al,P,S,Ti,V,Cr,Mn,Fe,Co,Cu,Nb,Mo,W共15种元素。对辉光放电参数如电流、电压、预溅射时间进行了优化;对高温合金中的质谱干扰进行了分析并详细叙述了各分析元素的干扰情况。选择丰度大且不受干扰或干扰少的同位素用于分析,大多数元素测定结果很好。对于仍存在干扰的元素通过数学校正的方法进行质谱干扰校正。建立干扰校正公式,成功地消除了62Ni2+和36Ar12C+对31P+和48Ti+的质谱干扰。在优化的实验条件下,建立工作曲线。