用NRTL方程预测三元,四元液态合金体系的热力学数据

ＮＲＴＬ方程是在化工热力学中广泛应用的方程之一,０「经的显著优点可以仅用二元数据预测三元系热力学性质。但该方程对于冶金过程中的液态合金及其它熔体的应用还极少见到。本文用ＮＲＴＬ方程差联以Ｃｄ－Ｂｉ－Ｓｎ,Ｃｄ－Ｂｉ－Ｐｂ,Ｃｄ－Ｓｎ－Ｐｂ液态合金体系所涉及的二元系活度系数数据,并对三元系活度数据和Ｃｄ－Ｂｉ－Ｐｂ－Ｓｎ四元系中Ｃｄ的活度进行了预测。     

用WiSon方程预测三元液态合金的热力学性质SCIEI

本文试图将Wilson方程应用于液态合金.研究结果表明该式只用二元系双分子相互作用参数就能简便地算出三元液态合金各组元的活度,其结果与实验数据基本一致,并且由经典热力学判别式验证是可靠的。因此,Wilson方程适用于预测液态合金的热力学性质。     

PREDICTION ON THERMODYNAMIC PROPERTIES OF TERNARY LIQUID ALLOYS FROM WILSON EQUATION

An attempt was made on applying the Wilson equation to predict the thermodynamic proper-ties of ternary liquid alloys.The activity of each component in ternary liquid alloys was foundto be conveniently calculated from the equation with the related binary bimolecular interactionparameters.The calculated values are in fair agreement with experimental data,and are veri-fied to be reliable by the criterion of classical thermodynamics.     

AN ASSESSMENT OF INTERACTION PARAMETERS IN BINARY METALLIC SYSTEMS

1.IntroductionTheinteractionparameterformalismfirstdevelopedbyWagnerisextensivelyusedtorepresentthethermodynamicpropertiesofdilutesolutionsparticularlyformetalalloys.Sointeractionparametersareindispensabletomakethermodynamicanalysisfortherelevantmeta...     

Ti-Al合金熔体与氧化物陶瓷界面反应的热力学分析(英文)

研究CaO、MgO、Al2O3和Y2O3与熔融Ti及Ti合金之间的界面反应热力学。根据氧化物在Ti合金熔体中的溶解反应机制建立热力学模型,通过热力学分析预测各氧化物相对于Ti-Al(0≤x(Al)≤0.5)合金的热力学稳定性。根据氧化物坩埚熔炼实验结果来研究氧化物与Ti-xAl合金熔体的界面反应,对熔炼效果进行定量分析,发现随着合金中Al含量的提高和熔体温度的降低,合金中杂质元素含量成比例的减少,这与氧化物稳定性计算结果一致。     

Prediction of surface and interfacial tension based on thermodynamic data and CALPHAD approach

In this article, following a brief introduction concerning experimental measurements of surface and interfacial tensions, methods for calculating surface tension and surface segregation for binary, ternary, and multicomponent high-temperature melts based on Bulter＇s original treatment [ 1] and on available physical properties and thermodynamic data, especially excess Gibbs free energies of bulk phase and surface phase versus temperature obtained from thermodynamic databases using the calculation of phase diagram （CALPHAD） approach, with special attention to the model parameter β, have been described. In addition, the geometric models can be extended to predict surface tensions of multicom- ponent systems from those of sub-binary systems. For illustration, some calculated examples, including Pb-free soldering systems and phase-diagram evaluation of binary alloys in nanoparticle systems are given. On the basis of surface tensions of high-temperature melts, interracial tensions between liquid alloy and molten slag as well as molten slag and molten matter can be calculated using the Girifalco-Good equation [2]. Modifications are suggested in the Nishizawa＇s model [3] for estimation of interracial tension in liquid metal （A）/ceramics （MX） systems so that the calculations can be carried out based on the sublattice model and thermodynamic data, without deliberately differentiating the phase of MX at high temperature. Finally, the derivation of an approximate expression for predicting interfacial tension between the high-temperature multicomponent melts, employing Becker＇s model [4] in conjunction with Bulter＇s equation and inteffacial tension data of the simple systems is described, and some examples concerning pyrometallurgical systems are given for better understanding.     

依据活度系数预测二元合金熔体的表面张力

提出了一种简便的方法，以液态合金的活度系数为桥梁，假设体相和表面相的活度系数与其相应的原子配位数有一定的对应关系，从已有的热力学数据出发，利用Miedema二元合金生成热模型，借用数学软件，先计算出液态合金各个组元在体相中的活度系数，再将活度系数代入Butler方程求得二元合金的表面张力，并以Fe-Cu、Fe-Ni、Cu-Ni三种二元体系为例进行了计算验证，其结果与已有文献中的实验值吻合较好。     

Densities of molten Ni-（Cr,Co, W） superalloys

In order to obtain more accurate density for molten Ni-（Cr, Co, W） binary alloy, the densities of molten pure Ni and Ni-Cr, Ni-Co, Ni-W alloys were measured with a sessile drop method. It is found that the measured densities of molten pure Ni and Ni-Cr, Ni-Co, Ni-W alloys decrease with increasing temperature in the experimental temperature range. The density of alloys increases with increasing W and Co concentrations while it decreases with increasing Cr concentration in the alloy at 1 773-1 873 K. The molar volume of Ni-based alloys increases with increasing W concentration while it decreases with increasing Co concentration. The effect of Cr concentration on the molar volume of the alloy is little in the studied concentration range. The accommodation among atomic species was analyzed. The deviation of molar volume from ideal mixing shows an ideal mixing of Ni-（Cr, Co, W） binary alloys.     

用改良密度法精密测量熔融Ni-Ta二元合金的液态密度

用改良密度法对熔融Ni—Ta二元合金的液态密度进行了精密测量。结果表明：熔融Ni-Ta二元合金的密度随温度的增加而减少，但随合金中钽浓度的增加而增加：熔融Ni-Ta二元合金的摩尔体积随温度和合金中钽浓度的增加而增加，并对钽在熔融Ni-Ta二元合金中的偏摩尔体积进行了计算。     

Bulk amorphous metal—An emerging engineering material

During the last two decades, researchers have developed families of metal alloys that exhibit exceptional resistance to crystallization in the undercooled liquid state. Upon cooling, these alloys readily form glass or vitrify to form bulk amorphous alloys or bulk metallic glasses. The stability of the undercooled molten alloys with respect to crystallization has enabled studies of liquid thermodynamics, rheology, atomic diffusion, and the glass transition previously not possible in metallic systems. Bulk amorphous alloys exhibit very high strength, specific strength, and elastic strain limit, along with unusual combinations of other engineering properties. These factors, taken together, suggest that bulk amorphous metals will become widely used engineering materials during the next decade.     

ASSESSMENT OF THERMODYNAMIC DATA AND STABILITY OF INTERMETALLIC COMPOUNDS

ＡＳＳＥＳＳＭＥＮＴＯＦＴＨＥＲＭＯＤＹＮＡＭＩＣＤＡＴＡＡＮＤＳＴＡＢＩＬＩＴＹＯＦＩＮＴＥＲＭＥＴＡＬＬＩＣＣＯＭＰＯＵＮＤＳ￥ＬＩＷｅｎｃｈａｏ;ＬＩＸｉｎｇｋａｎｇ;ＷＡＮＧＪｉａｎ;ＺＨＯＵＧｕｏｚｈｉ（ＵｎｉｖｅｒｓｉｔｙｏｆＳｃｉｅｎｃ...     

In-Bi-Tl三元系液体合金中成分的活度测定SCIEI

用ZrO_2固体电解质组成氧浓差电池:(-)Re,In,In_2O_3|ZrO_2(Y_2O_3)|In-Bi-Tl,In_2O_3,Re(+),在973—1223K的温变范围内测定了In-Bi-Tl三元系中含Tl量较少的两个mol比(N_(Bi)/N_(Tl))一定的拟二元系合金中In的活度,据实验结果求得合金的过剩自由能。使用作者曾提出的计算式及有关各二元系热力学数据计算了合金中In的活度及过剩自由能。计算值与实验值相当一致。此三元系合金的过剩自由能除在In-Tl二元系相近组成以外都呈负值,极小值在Bi-Tl二元系上。     

金属合金溶液热力学模型研究进展

对二元合金热力学数据的拟合和预测模型，由二元系数力学性质预测三元系热力学性质模型，以及多元溶液组元的活度相互作用参数表达式等金属合金溶液热力学模型的研究历史和目前进展进行了全面阐述，并对各模型的特征进行了评述。     

Bulk and Surface Properties of Liquid Cr-Nb-Re Alloys

Experimental determination of thermodynamic and thermophysical properties of both solid and, in particular, liquid alloys at high temperatures is often technically difficult or even impossible, and therefore theoretical models can be used to estimate missing property values. Preliminary inspection of the literature related to the Cr-Nb-Re system and its binary subsystems reveals mainly theoretical results obtained in the framework of different theories, but the corresponding experimental property data are still sparse. The energetics of mixing in liquid Cr-Nb, Cr-Re and Nb-Re systems has been analysed through the study of the concentration dependence of various thermodynamic, surface (surface tension and surface composition) and structural properties (concentration fluctuations in the long-wavelength limit and chemical short-range order parameter) by the first or the quasi-chemical approximation for regular solutions, developed by Bhatia and Singh, in the framework of statistical mechanical theory in conjunction with the quasi-lattice theory. The results obtained for these binary systems have been extended to study the thermodynamics and surface properties of ternary Cr-Nb-Re liquid alloys.     

用Wilson方程估算多元液态合金在给定温度下的组元活度

根据Ｗｉｌｓｏｎ参数与温度的关系，可将Ｗｉｌｓｏｎ方程扩展到只利用不同温度下测定的二元液太民合金各组元的活度，估算出给定温度下二元和多元液态合金各组元的活度，研究结果表明，多元液太民合金的活度算值与其实验数据和符合良好。     

THE BASIC CONSIDERATIONS OF SELF-SReM AND SELF-BoSS MODELS

1. IntroductionComponent activity in metallurgical melts is one of the key projects in the investigationof thermodynamics. It is fully possible to apply the thermodyllamic principle for theoptimization or development of various metallurgical processes. However, the shortageof thermodynamic data in concentrated multicomponent systems frequently results in thelimitation of these applications.Traditionally, running experiment is the sole way to get the data of component activities on several poin…     

铁锰二元合金耐液锌腐蚀机理

研究了四种不同Mn含量的铁锰二元合金在450℃液锌中的腐蚀行为,探讨了Mn对铁锌反应的影响规律。结果表明,铁锰二元合金在液锌中的腐蚀属于溶解性腐蚀。随着锰含量的增加,腐蚀速率有较大变化。含锰量为10wt%的合金,其腐蚀速率为5.79×10-3g.cm-2.h-1,含锰量为15wt%的合金,其腐蚀速率为3.64×10-2.gcm-2.h-1。锰含量为10wt%时,腐蚀产物由致密的δ相层和块状的ζ相层组成,致密的较厚的δ相层的存在,降低了铁锌反应速率,合金表现出较好的耐液锌腐蚀能力,而锰含量为15wt%时,腐蚀产物由大量疏松的颗粒状ζ相分布在液锌相中组成,疏松的组织恶化了合金的耐液锌腐蚀能力。     

二元合金热力学模型—Miedema模型

由于只需几个物性参数和设定常数,Miedema模型就能简单地计算二元合金液相或者固相的热力学数据,而且计算值与实验值吻合度较高,因而被广泛应用于二元合金热力学的计算。在介绍了该理论的物理模型的基础上详细阐述了Miedema半经验公式的推导以及物性参数和常数的确定,并对此模型的应用和误差做了客观的分析和总结。     

Thermodynamics of particle coarsening

The coarsening of precipitate particles during the heat treatment of alloys depends both on the diffusivity of the surrounding phase and on the concentration differences given by the Gibbs-Thomson equation, both of which depend on the solution thermodynamics of the surrounding phase. However, it is now known that thermodynamic terms cancel in the theory; therefore coarsening is independent of solution behavior. The equations that confirm this prediction for multicomponent systems are derived and discussed. In addition, it is shown for ternary and higher order systems that a generalized form of the Gibbs-Thomson equation gives a vector that is normal to the matrix-precipitate phase diagram boundary.