Application of the annexation principle to the study of thermodynamic properties of ternary metallic melts In-Pb-Ag and In-Bi-Sb

Based on the phase diagrams, measured activities and the annexation principle, the calculating models of mass action concentrations for In-Pb-Ag and In-Bi-Sb ternary metallic melts have been formulated. The results of calculation both agree with practice, and obey the law of mass action, showing that the models formulated can reflect the structural reality of the corresponding melts and the annexation principle is applicable to the them.     

Application of annexation principle to the study of thermodynamic properties of ternary molten salts CaCl_2-MgC_2-NaCl

Based on the practical basis of measured activities and phase diagrams as well as in the light of the mass action law, the model of inseparable cations and anions of molten salts and mattes, and the annexation principle of two kinds of solutions in binary melts, the calculating model of mass action concentrations of molten salts CaCl_2-MgCl_2-NaCl was formulated. The results of calculation not only agree with experimental values, but also obey the mass action law, testifying that the model formulated can embody the structural characteristics of these ternary salts, and that the model of inseparable cations and anions as well as the annexation principle of two kinds of solutions in binary melts are also appficable to these ternary salts.     

Application of annexation principle to the study of thermodynamic properties of ternary molten salts CaCl2-MgCl2-NaCl

Based on the practical basis of measured activities and phase diagrams as well as in the light of the mass action law, the model of inseparable cations and anions of molten salts and mattes, and the annexation principle of two kinds of solutions in binary melts, the calculating model of mass action concentrations of molten salts CaC12-MgCl2-NaCl was formulated. The results of calculation not only agree with experimental values, but also obey the mass action law, testifying that the model formulated can embody the sauctural characteristics of these temary salts, and that the model of inseparable cations and anions as well as the annexation principle of two kinds of solutions in binary melts are also applicable to these ternary salts.     

Effect of peritectics on thermodynamic properties of homogeneous binary metallic melts

1　ＩＮＴＲＯＤＵＣＴＩＯＮＩｎＲｅｆｓ.[1～ 5 ],ｃｌｅａｒｉｌｌｕｓｔｒａｔｉｏｎｓｏｆｔｈｅｔｈｅｒ ｍｏｄｙｎａｍｉｃ ｐｒｏｐｅｒｔｉｅｓｏｆｍｅｔａｌｌｕｒｇｉｃａｌｍｅｌｔｓｈａｖｅｂｅｅｎｍａｄｅ .ＩｎＲｅｆ .[6 ],ｔｈｅｐｒｅｓｅｎｃｅｏｆｐｅｒｉｔｅｃｔｉｃｉｎｂｉｎａｒｙｍｅｔａｌｌｉｃｍｅｌｔｓｈａｓｂｅｅｎｄｅｍｏｎｓｔｒａｔｅｄｉｎｄｅｔａｉｌ.Ｈｏｗｅｖｅｒ ,ｄｕｅｔｏｃｕｓｔｏｍａｒｙｍｉｓｕｎｄｅｒｓｔａｎｄｉｎｇｏｆｔｈｅｐｈａｓｅｄｉａｇｒａｍｓ :ｃｏｎｓｉｄｅｒ…     

Thermodynamic properties and mixing thermodynamic parameters of Ba-Al, Mg-Al, Sr-Al and Cu-Al metallic melts

Application of equations of mixing thermodynamic parameters formulated on the basis of the coexistence theory of metallic melts in Ba-Al, Mg-Al, Sr-Al and Cu-Al melts leads to fruitful results that not only the evaluated mass action concentrations agree well with the measured activities, but also the calculated mixing thermodynamic parameters are quite coincident with the experimental values. Moreover, the calculated mass action concentrations strictly obey the mass action law. The evaluated mixing thermodynamic parameters have very fine regularity: the mixing free energy is composed of standard free formation energies of all compounds and chemical potentials of all structural units at equilibrium; the mixing enthalpy consists of standard formation enthalpies of all compounds; the mixing entropy is composed of standard entropies of all compounds and configuration entropies of all structural units at equilibrium. As the equations of mixing thermodynamic parameters formulated are widely applicable to metallic melts involving compound formation, they can be used as the second practical criterion to determine whether thermodynamic models of metallic melts are correctly formulated.     

Thermodynamic properties and mixing thermodynamic parameters of binary homogeneous metallic melts

After the investigation on the thermodynamic properties and mixing thermodynamic parameters of binary homogeneous metallic melts involving compound, peritectic as well as solid solution, it was found that the equations of mixing free energy △Gm and excess free energy △Cxs of them can be expressed by the following equations: and △GxS =△Gm -RT(alna + blnb), respectively.     

ANNEXATION OF TWO KINDS OF SOLUTION IN BINARY METALLIC MELTS

After investigation on the thermodynamic properties of a small number of binary metallic melts,the structural units of which cannot be wholly determined by the corresponding phase diagrams, it was found that they can be determined by the principle of annexation of two kinds of solutions in binary metallic melts.According to the principle of annexation, calculating models of mass action concentrations for several binary metallic melts have been formulated.The calculated results agree well with practice,showing that this principle is a reliable basis for determination of the structural units for some binary metallic melts.     

Calculating model of mass action concentrations for Ag-Au-Cu melts

Based on phase diagrams and measured activities, the calculating model of mass action concentrations for heterogeneous melts Ag-Au-Cu was formulated. Calculated results agree with the improved results of recent research work,showing that the model formulated can reflect the structural characteristics of these melts. In this model, without the help of any empirical parameters, only three equilibrium constants are used, hence it is simple, lear, and favorable to the simplification of calculation.     

Determination of thermodynamic properties in full composition range of Ti-Al binary melts based on atom and molecule coexistence theory

The results of predicting thermodynamic properties in the full composition range of Ti-Al binary melts in a temperature range from 1973 to 2273 K were obtained by coupling with the developed thermodynamic model for calculating mass action concentration N_i of structural units in Ti-Al system based on the atom and molecule coexistence theory (AMCT). Temperature dependence of the activity coefficients of Ti and Al in natural logarithmic form in the infinitely dilute solution (0>x_Ti<0.01) of Ti-Al binary melts was also determined from the calculated activity coefficients of Ti and Al at temperatures of 1973, 2073, 2173, and 2273 K. The standard molar Gibbs free energy change of dissolving pure liquid element i(l) for forming 1% (mass fraction) element i in Ti-Al binary melts further was deduced. With the aid of this model, meanwhile, the determined excess thermodynamic properties, such as the excess molar mixing Gibbs free energy/entropy/enthalpy were also calculated.     

Applicability of law of mass action to distribution of manganese between slag melts and liquid iron

1　ＩＮＴＲＯＤＵＣＴＩＯＮＭａｎｇａｎｅｓｅｉｓａｗｉｄｅｌｙｕｓｅｄａｌｌｏｙｅｌｅｍｅｎｔａｎｄｒｅ ｄｕｃｉｎｇａｇｅｎｔ,ｉｔｓｄｉｓｔｒｉｂｕｔｉｏｎｂｅｔｗｅｅｎｓｌａｇｍｅｌｔｓａｎｄｌｉｑｕｉｄｓｔｅｅｌｍａｙｓｅｒｖｅａｓｉｎｄｉｃａｔｏｒｏｆｓｔｅｅｌｂａｔｈｔｅｍ ｐｅｒａｔｕｒｅ .Ｈｅｎｃｅ ,ｍａｎｇａｎｅｓｅｄｉｓｔｒｉｂｕｔｉｏｎｂｅｔｗｅｅｎｓｌａｇｍｅｌｔｓａｎｄｌｉｑｕｉｄｉｒｏｎｐｒｏｖｏｋｅｄｇｒｅａｔｉｎｔｅｒｅｓｔｏｎｔｈｅｐａｒｔｏｆｍｅｔａｌｌｕｒｇｉ…     

APPLICATION OF THE ANNEXATION PRINCIPLE TO THE STUDYOF THERMODYNAMIC PROPERTIES OF TERNARY METALLICMELTS Cd-Pb-Sb

1. IntroductionThe thermodynamic properties of binary metallic melts have been c1early illustrated inRefs.[1-5]. Further work is to formulate calculating model8 of thermodynamic propertiesfor melts consisting of more than three components, especially for multicomponent meltsinvolving different kinds of binary metallic melts with sufficient application of thermody-namic properties of binary systems. The goal of this paper is to formulate the calculatingmodel of mass action concentrations for te…     

A new method for calculating the activity of stable compound from binary phase diagram

1. Introduction It is a very important way of gaining activity from a phase diagram. Wagner [1] pointed out that calcu- lating the thermodynamic properties from a phase diagram is important because the measurement of solid and liquid phase lines is easier than that of thermodynamic properties. Rihcardson [2] also pointed out that it is necessary to obtain information from a phase diagram as much as possible for the lacking of the datum of Gibbs energy and activity in high temperature solution.…     

Local structure of calcium silicate melts from classical molecular dynamics simulation and a newly constructed thermodynamic model

The distributions of local structural units of calcium silicate melts were quantified by means of classical molecular dynamics simulation and a newly constructed structural thermodynamic model. The distribution of five kinds of Si-O tetrahedra Q_i from these two methods was compared with each other and also with the experimental Raman spectra, an excellent agreement was achieved. These not only displayed the panorama distribution of microstructural units in the whole composition range, but also proved that the thermodynamic model is suitable for the utilization as the subsequent application model of spectral experiments for the thermodynamic calculation. Meanwhile, the five refined regions mastered by different disproportionating reactions were obtained. Finally, the distributions of two kinds of connections between Q_i were obtained, denoted as Q_i-Ca-Q_j and Q_i-[O_b]-Q_j, from the thermodynamic model, and a theoretical verification was given that the dominant connections for any composition are equivalent connections.     

APPLICABILITY OF THE MASS ACTION LAW IN COMBINATION WITH THE COEXISTENCE THEORY OF METALLIC MELTS INVOLVING COMPOUND TO BINARY METALLIC MELTS

Based on the atomicity and rnolecularity as well as the consistency of thermodynamic properties and activities of metallic melts with their structures, the coexistence theory of metallic melts structure involving compound has been suggested. According to this theory, the calculating models of mass action concentrations for different binary metallic melts have been formulated. The calculated mass action concentrations agree well with corresponding measured activities, which confirms that the suggested theory can reflect the structural characteristics of metallic melts involving compound and that the mass action law is widely applicable to this kind of metallic melts.     

CALCULATING MODELS OF MASS ACTION CONCENTRATIONS FOR MATTES (Cu_2S-FeS-SnS)INVOLVING EUTECTIC

1.IntroductionMattesareimp0rtantintermediateproductsintheextracti0n0fc0pper)nickelandleadfromtheirconcentrates.Muchresearchw0rkhasbeendoneinthetechn0l0gy0fextraction-However,littleiskn0wnab0utthetherm0dynamicpropertiesofmattes,especiallyabouttheactivities0fmattes.lthadbeensh0wnthatcati0nsandanionsofmoltensaltsaswellasbinarybasicoxides0lids0luti0nsd0n0tsepaxatefromeach0ther0naccount0ftheirgreatelectricconductivities,hencebeingsh0rt0fdielectricmedium,soastoreducethestr0ngattractiveforcesbetweenc…     

熔锍作用浓度计算模型初探

根据熔盐和氧化物固溶体中正负离子未分开和熔锍电导大于熔盐和氧化物固溶体的事实，按照正负离子未分开的原则制定了含共晶体和含复杂化合物二元熔锍的作用浓度计算模型，计算结果符合实际，从而证明所制定的模型可以反映相应二元熔锍的结构本质。     

铝合金可锻性及热力学参数确定原则分析

对铝及铝合金可锻性进行了分析,在此基础对铝及铝合金的热力学参数—锻造温度、锻造速度、变形程度等的确定原则进行了分析,列举了国内外常用铝合金的锻造工艺参数,可供生产实践参考。     

Mg-Al-Zn-Sm合金的组织、力学性能及其热力学分析

利用相图热力学数据库设计Mg-Al-Zn-Sm系合金的成分和热处理工艺。合金经熔炼铸造后进行T6工艺热处理。通过硬度测试确定合金的峰时效点,并在峰时效点进行室温拉伸实验。结果表明:成分为Mg-6Al-1.3Sm-1Zn(质量分数,%)的样品时效后的抗拉强度(σb)为263 MPa。采用X射线衍射(XRD)和透射电子衍射(TEM)并结合X射线能谱分析方法确定合金基体为Mg-Zn固溶体,析出相为Mg17Al12与Al2Sm。借助金相光学显微技术与扫描电镜(SEM)对合金的微观组织形貌进行分析,并采用热力学计算对显微组织的形成进行解释。示差扫描量热技术(DSC)测试结果表明:合金凝固过程中的相变点与计算模拟的结果吻合。     

Effect of nonlinear liquidus and solidus on dendrite growth in bulk undercooled melts

On the base of nonlinear liquidus and solidus,an extended model for dendrite growth in bulk undercooled melts was developed under local non-equilibrium conditions both at the interface and in the bulk liquid.In terms of thermodynamic calculations of the phase diagram,the model predictions are relatively realistic physically,since few fitting parameters are used in the model predictions.Adopting three characteristic velocities,i.e.the critical velocity of absolute solute stability(VC*),the velocity of maxima...     

Derivation of the phase field equations from the thermodynamic extremal principle

Thermodynamics employs quantities that characterize the state of the system and provides driving forces for system evolution. These quantities can be applied by means of the thermodynamic extremal principle to obtain models and consequently constitutive equations for the evolution of the thermodynamic systems. The phase field method is a promising tool for simulation of the microstructure evolution in complex systems but introduces several parameters that are not standard in thermodynamics. The purpose of this paper is to show how the phase field method equations can be derived from the thermodynamic extremal principle, allowing the common treatment of the phase field parameters together with standard thermodynamic parameters in future applications. Fixed values of the phase field parameters may, however, not guarantee fixed values of thermodynamic parameters. Conditions are determined, for which relatively stable values of the thermodynamic parameters are guaranteed during phase field method simulations of interface migration. Finally, analytical relations between the thermodynamic and phase field parameters are found and verified for these simulations. A slight dependence of the thermodynamic parameters on the driving force is determined for the cases examined.