Determination of the Composition of the Surface Layer of Binary Metal Alloys

We have analyzed the effect of various parameters (surface tensions of the components, molar volumes of the components and the solution, compression and depression in alloy formation, activity coefficients of the components in the melt) on the shape of the surface tension isotherm as a function of the surface layer composition. We compare the analysis results with experimental data. We propose a method for estimating the composition of the surface layer based on a model assuming an additive variation in the surface tension of the solution as a function of the composition of the surface layer. We have calculated the concentration of the surface-active component in the surface layer of melts in the systems Ge - Sn, Ge - Pb, and Ge - Bi.__________Translated from Poroshkovaya Metallurgiya, Nos. 1–2(441), pp. 60–67, January–February, 2005.     

铁浴式熔融还原型熔体的性质

研究了铁浴式熔融还原型熔体的组成与性质的关系，测试了熔体对耐火材料的浸润性，分析了熔体中ＦｅＯ浓度，熔体温度，耐火材料的组成及结构，耐火材料中石墨碳含量等对熔体与耐火材料间浸润性的影响，同时测试了熔体组成与流动性的关系，熔体中ＦｅＯ浓度，熔渣碱度对熔体的熔化温度的影响，测定和分析了熔体组成与粘度变化的关系，结果表明，熔中ＦｅＯ浓度是影响熔体性质的最关键因素，ＦｅＯ浓度提高，熔体对耐火材料的润湿能力     

Mathematical Viscosity Models for Ternary Metallic and Silicate Melts

The mathematical viscosity models for metallic melts were discussed. The experimental data of Ag-Au-Cu systems were used to verify the models based on Chou‘s general geometric thermodynamic model and the calculated results are consistent with the reported experimental data. A new model predicting the viscosity of multi-component silicate melts was established. The CaO-MnO-SiO2, CaO-FeO-SiO2 and FeO-MnO-SiO2 silicate slag systems were used to verify the model.     

Thermodynamics of the oxygen solutions in chromium-containing Ni–Co melts

A thermodynamic analysis of the oxygen solutions in chromium-containing Ni–Co melts at 1873 K has been performed. The equilibrium constants of reactions between chromium and oxygen, the activity coefficients at infinite dilution, and the interaction parameters for melts differing in composition have been determined. The dependences of the oxygen solubility on the cobalt and chromium contents in the melts are calculated. The deoxidizing capacity of chromium slightly decreases as the cobalt content in the melt increases. The composition dependences of the oxygen solubility in the chromium-containing Ni–Co melts have a minimum, which shifts to a high boron content as the cobalt content in the melts increases. The further increase in the chromium addition leads to an increase in the oxygen content in the melt.     

铝及其合金熔体净化技术的实践

本文分析了铝熔体中氢与Al2O3夹杂物的来源及相互作用．提出了铝熔体净化必须“除气除渣同时进行，除渣是除气的前提”的原则．介绍了气体 精炼剂-气体-过滤综台净化技术．及提高铝熔体净化效果的新技术途径。     

Thermodynamic Simulation of the A<Superscript>III</Superscript>–B<Superscript>V</Superscript> Semiconductor Melts

The equilibrium compositions and the thermodynamic characteristics of binary Ga–Sb, Al–Sb, and In–Sb melts are studied by a thermodynamic simulation using the TERRA software package over wide temperature and composition ranges. The temperature dependences of the partial pressures of the components of the gas phase forming above the III–V (III = Ga, In; V = Sb) semiconductor melts are investigated. The concentration dependences of the component activities and the partial and integral characteristics of melt mixing are obtained. All melts under study are shown to exhibit large negative deviations from Raoult’s law, which is caused by the presence of associates and indicates a strong interaction between the melt components. The temperature dependences of the logarithms and the partial pressures of the gas phase components are obtained. These dependences are shown to be linear for the components of the gas phase forming over the Ga–Sb, Al–Sb, and In–Sb melts.     

Thermodynamic behaviour of phosphorus in Mn-Si-Ca-P melts

Thermodynamic experiments of Mn-Si-Ca-P melts were carried out in Mo-wire-heated furnace. With these experimental data, the first and second order activity interaction coefficients of Ca, Si and P upon P under the conditions of the same activity and the same concentration method were evaluated. The standard free energy of solution of P in liquid Mn based on 1 wt.% solution standard formulated in temperature was given and it only holds near 1623 K.     

Oxygen solubility in silicon-containing Fe-Co melts

Thermodynamic analysis of the oxygen solutions in silicon-containing Fe-Co melts is performed. The equilibrium constant of silicon deoxidation of iron-cobalt melts, the activity coefficients for infinite dilution, and the interaction parameters for melts differing in composition are determined. The dependences of the oxygen solubility in the melts under study are calculated for different cobalt and silicon contents. The deoxidizing capacity of silicon increases substantially as the cobalt content in a melt increases. The curves of oxygen solubility in Fe-Co melts have a minimum; the minimum oxygen solubility shifts to a low silicon content as the cobalt content in the melts increases. The silicon contents for the minima in the curves of oxygen solubility and the minimum oxygen concentrations corresponding to the silicon contents are determined.     

Thermodynamics of the oxygen solutions in the aluminum-containing Ni–Co melts

A thermodynamic analysis of the oxygen solutions in the aluminum-containing Ni–Co melts has been performed. The equilibrium constants of reactions of aluminum deoxidation of nickel-cobalt melts, the activity coefficients at infinite dilution, and the interaction parameters for the melts differing in composition at 1873 K have been determined for the first time. The dependences of the oxygen solubility on the cobalt and aluminum contents in the melts are calculated. The deoxidizing capacity of aluminum slightly varies as the cobalt content in a melt increases to 20%; at higher cobalt contents in the melts, it increases substantially. The aluminum contents at the minima in the oxygen solubility curves and the oxygen contents corresponding to the aluminum contents have been determined.     

Advances in Investigation of Fe-based Glass-forming Alloy Melts

Continuous precision casting is an important trend in modern industrialization.Clustering effects in glassforming metallic liquids tremendously influence the properties of rapidly quenched ribbons;therefore,much attention has been paid to the study of Fe-based glass-forming melts at high temperatures.Recent investigations of these melts are categorized and reviewed.It is concluded that more efforts are still required to reveal the discipline of amorphization brought about by rapid quenching of Fe-based glass-forming melts.     

Thermodynamics of the oxygen solutions in boron-containing Fe–Co melts

A thermodynamic analysis of the oxygen solutions in boron-containing Fe–Co melts has been performed. The equilibrium constant of reaction between boron and oxygen, which are dissolved in iron–cobalt melts; the activity coefficients at infinite dilution; and the interaction parameters for melts differing in composition have been determined. The oxide phase formed in the Fe–Co melts containing boron and oxygen comprises FeO and CoO along with the B₂O₃ phase. The oxide phase compositions over Fe–Co–B–O melts are calculated. As the cobalt and boron contents in the melts increase, the mole fraction of boron oxide increases; in the case of pure cobalt, it is close to unity. The dependences of the oxygen solubility on the cobalt and boron contents in the melts are calculated. The deoxidizing capacity of boron substantially increases as the cobalt content in a melt increases. The composition dependences of the oxygen solubility in boron-containing Fe–Co melts have a minimum, which shifts to a low boron content as the cobalt content in the melts increases. The boron contents corresponding to the minimum in the oxygen solubility curves and the minimum oxygen concentrations corresponding to the boron contents are determined.     

Thermodynamics of the oxygen solutions in niobium-containing Fe-Ni melts

A thermodynamic analysis is performed for the oxygen solutions in niobium-containing Fe-Ni melts. The deoxidizing capacity of niobium in iron??nickel melts is shown to be low. It decreases slightly as the nickel content in a melt increases to 40% and then increases insignificantly as the nickel content increases to 60%; a further increase in the nickel content leads to a marked increase in the deoxidizing capacity. The solubility curves of oxygen in iron??nickel melts passes through a minimum, whose position shifts toward higher niobium concentrations with increasing nickel content. Subsequent niobium additions increase the oxygen concentration in the melt. The equilibrium constants of the reactions of niobium deoxidizing of iron??nickel melts, the activity coefficients, and the interaction parameters characterizing Fe-Ni-Nb-O melts are determined.     

Thermodynamics of the oxygen solutions in aluminum-containing Fe-Co melts

Thermodynamic analysis of aluminum-containing Fe-Co melts is performed. The equilibrium constants of the deoxidation of iron-cobalt melts with aluminum, the activity coefficients during infinite dilution, and the interaction parameters in melts with various compositions are determined. The oxygen solubility in the melts under study is studied as a function of the cobalt and aluminum contents. Aluminum is characterized by a very high affinity to oxygen in iron-cobalt melts. The deoxidizing capacity of aluminum substantially increases with the cobalt content in the melt. The curves of the oxygen solubility in aluminum-containing iron-cobalt melts have a minimum, whose position shifts to lower aluminum contents as the cobalt content in the melt increases. Further aluminum additions increase the oxygen concentration in the melt: the higher the cobalt content in the melt, the sharper the increase in the oxygen concentration after the minimum when aluminum is added to the melt. The aluminum contents at the minimum points in the oxygen solubility curves are determined, and the corresponding minimum oxygen concentrations are found.     

Thermodynamics of the oxygen solutions in zirconium-containing iron-nickel melts

Thermodynamic analysis of the oxygen solutions in zirconium-containing iron-nickel melts is carried out. The equilibrium deoxidation constants of the melts by zirconium, the activity coefficients at infinite dilution, and the interaction parameters in melts of various compositions are determined. The dependences of the oxygen solubility in the melts on the nickel or zirconium content are calculated. Zirconium is shown to possess a very high deoxidizing capacity in iron-nickel alloys. The zirconium contents at the minima in oxygen solubility curves and the corresponding minimum oxygen concentrations are determined. As the nickel content in a melt increases to ∼45%, the deoxidizing capacity of zirconium decreases and, then, increases. The deoxidizing capacity of zirconium in pure nickel is noticeably higher than that in pure iron.     

Relationship Between Activity Interaction Parameters in Fe-C System and Temperature

Carbon solubility in Fe-Mn melts (xFe=0.102 3-0. 789 9, xMn=0.055 1-0.638 0) was measured exper-imentally at various temperatures. Using Gibbs-Duhem equation, in combination with the experimental results in this work, quoting experimental data reported in references, and by strict thermodynamic derivation and calculation, the relation equations between the activity interaction parameters in Fe-C system and temperature were obtained. The calculation equation of InγFe> in Fe-C system was also obtained. The calculated results show that these relation equa-tions can be used to calculate the activity coefficients of carbon and iron in Fe-C system and can satisfy the necessary condition to satisfy Gibbs-Duhem equation and the necessary condition to satisfy the stability condition of system at high carbon content. The calculation formula for Inγc in Fe-Mn-C system was also obtained.     

Thermodynamics of the oxygen solutions in manganese-containing Fe-Co melts

Thermodynamic analysis of the oxygen solutions in manganese-containing Fe-Co melts has been performed. The equilibrium constants of deoxidation reaction of iron-cobalt melts with manganese, the activity coefficients during infinity dilution, and the interaction parameters in various melts are found. During the deoxidation of manganese-containing Fe-Co melts, the oxide phase contains FeO and CoO along with MnO. The compositions of the oxide phase above Fe-Co-Mn-O melts are calculated. When the cobalt and manganese contents in the melts increase, the mole fraction of manganese oxide increases, and it approaches 1 in the case of pure cobalt. The dependences of the oxygen solubility in the melts on the cobalt and manganese contents are calculated. The deoxidizing capacity of manganese increases substantially with increasing cobalt content in the melt. The curves of oxygen solubility in Fe-Co melts have minima, whose values shift toward low manganese content in a melt. The manganese contents are determined at the minimum points in the oxygen solubility curves, and the corresponding minimum oxygen contents are found.     

Fe—C—P,Fe—Mn—P,Fe—Si—P三元金属熔体作用浓度计算模型

根据含化合物的金属熔体结构的共存理论，推导了１６７３Ｋ下Ｆｅ－Ｃ－Ｐ、Ｆｅ－Ｍｎ－Ｐ、Ｆｅ－Ｓｉ－Ｐ三元金属熔体作用浓度计算模型。计算的磷的作用浓度与相应的实测磷活度相符合，从而证明所得模型可以反映Ｆｅ－Ｃ－Ｐ、Ｆｅ－Ｍｎ－Ｐ、Ｆｅ－Ｓｉ－Ｐ三元熔体的结构本质。同时模型揭示了Ｃ、Ｍｎ、Ｓｉ的摩尔分数对磷的转换系数的影响规律。     

Thermodynamics of the oxygen solutions in iron-nickel melts

The oxygen solutions in Fe-Ni melts containing chromium, manganese, vanadium, carbon, silicon, titanium, or aluminum are studied thermodynamically. The equilibrium constants of the deoxidation of the melts by these elements are determined, and the activity coefficients for infinite dilution and the interaction parameters in alloys of various compositions are found. The oxygen solubilities in the alloys are calculated as a function of the nickel and deoxidizer contents. The deoxidizer contents at the minima in the oxygen solubility curves for the melts are determined, and the corresponding minimum oxygen concentrations are calculated. As the nickel content in the system increases, the deoxidizing capacities of chromium, manganese, and silicon are shown to increase substantially, and the deoxidizing capacity of carbon increases most strongly. As the nickel content in the melt increases, the deoxidizing capacities of vanadium and titanium first decrease insignificantly and then increase substantially. As the nickel content in the melt increases to 50%, the deoxidizing capacity of aluminum first decreases and then increases; in pure nickel, it is identical to that in pure iron.     

Thermodynamics of Fe-C-j （j=Al, Si, P, S） Melts

Based on a proposed method, the mathematical expressions between carbon solubility in Fe-C-j (j = Al, Si, P, S) melts and temperature were obtained. The expressions show the relation of the affecting factors of component j and temperature on carbon solubility, and the activity interaction coefficient of j upon carbon depends on atomic number, covalent radius and electro-negativity. The affecting factors of four elements on carbon solubility are all negative. There is a linear relationship between covalent radius and electro-negativity.     

含钡二元合金熔体热力学性质的计算

根据Miedema二元合金生成热模型，结合相关热力学数据，对Si-Ca二元合金熔体在1623K时的组元活度进行了计算，计算结果与实测结果吻合较好。并进一步对Ba-Si、Ba-Al和Ba-Ca3种二元含钡合金熔体的生成热△H及1873K时的过剩熵S^E、过剩自由能G^E以及不同温度下各组元的活度等热力学性质进行了计算。结果表明：3种合金的△H、S^E和G^E均为负值，且S^E绝对值的最大值为4．424J／mol，可以近似认为3种合金熔体的S^E为零；Ba-Si和Ba-Al合金熔体的活度相对于理想溶液存在较大负偏差，而Ba-Ca合金熔体的活度与理想溶液偏差较小。