Ni-Ga二元系的热力学计算

采用CALPHAD技术评估了Ni-Ga二元系的相图和热力学性质.用双亚晶格模型描述2个有序相(L1₂-Ni₃Ga和B₂-NiGa)的热力学行为,并在优化过程中考虑了fcc-(Ni)和L1₂Ni₃Ga相的有序-无序转变.溶液相(液相、fcc-(Ni)固溶体)的热力学模型采用Redlich-Kister方程,其余5个中间化合物被视为整比化合物.     

Thermodynamic Modeling of the Al-Ti-V Ternary System

The sub-binary systems Al-Ti, Ti-V, and Al-V are reviewed and adopted from the previous assessments, the thermodynamic analysis of the Al-Ti-V ternary system is performed by the CALPHAD approach, and a set of self-consistent thermodynamic parameters of the ternary system are obtained. Furthermore, the isothermal sections of this system at 1073 K, 1173 K, 1273 K, 1373 K, and 1473 K (800 °C, 900 °C, 1000 °C, 1100 °C, and 1200 °C) and the ternary invariant equilibria are calculated and compared with the corresponding experimental data, and all are in good agreement with most of the experimental results. Thus, the optimized thermodynamic parameters in this study may provide more accurate guidance to develop the new alloys involving it.     

Experimental Investigation and Thermodynamic Modeling of the Ag-Cu-Ge System

Metallurgical and Materials Transactions A - The liquidus surface projection was re-investigated using scanning electron microscopy with energy dispersive spectrometer and differential thermal...     

Experimental Investigation and Thermodynamic Modeling for the Mg-Nd-Sr System

Microstructure examination, phase analysis, and DSC measurement on the equilibrated ternary alloys not only enabled exploration of the phase equilibria relations of the Mg-Nd-Sr ternary but also thermodynamic assessment of the ternary system in the context of the CALPHAD approach. Thermodynamic modeling, further coupled with first principle calculations, was thereafter used to predict a panoramic phase diagram for the Mg-Nd-Sr ternary system at the Mg-rich corner.     

A Critical Evaluation and Thermodynamic Optimization of the CaO-CaF2 System

A critical evaluation and thermodynamic optimization of all the available literature experimental data of the CaO-CaF₂ system was conducted to obtain a set of thermodynamic functions which can reproduce all available and reliable experimental phase diagrams and thermodynamic data. The liquid solution was described using the Modified Quasichemical Model which assumes the mixing of O² and F^? in the pseudo anionic sublattice and CaF₂ solid solution was described using the compound energy formalism. The discrepancies in the CaO and CaF₂ liquidii among the available experimental data were resolved. The recent experimental data on the solubility of CaO in solid CaF₂ phase were well reproduced, which is critical to explain the eutectic temperature of the system.     

赛隆(Sialon)体系热力学性质评估与预报

利用拟抛物面规则编制了评估和预报热力学性质的计算机程序,较为系统地预报了β‘－Ｓｉａｌｏｎ,ｏ’－Ｓｉａｌｏｎ,Ｘ－Ｓｉａｌｏｎ,Ｓｉａｌｏｎ多形体以及α－Ｓｉａｌｏｎ等化合物的标准吉布斯自由能与温度的关系式,以及等温条件下标准吉布自由能与组份的关系式。这为赛隆材料的设计提供了热力学数据。     

Phase Stability in the Mo-Ti-Zr-C System via Thermodynamic Modeling and Diffusion Multiple Validation

Alloys in the Mo-rich corner of the Mo-Ti-Zr-C system have found broad applications in non-oxidizing environments requiring structural integrity well beyond 1273 K (1000 °C). Alloys such as TZM (Mo-0.5Ti-0.08Zr-0.03C by weight %) and TZC (Mo-1.2Ti-0.3Zr-0.1C by weight) owe much of their high temperature strength and microstructural stability to MC and M₂C carbide phases. In turn, the stability of the respective carbides and the subsequent mechanical behavior of the alloys are strongly dependent on the alloying additions and thermal history. A CALPHAD-based thermodynamic modeling approach is employed to develop a quaternary thermodynamic database for the Mo-Ti-Zr-C system. The thermodynamic database thus developed is validated with diffusion multiple experiments and the validated database is exercised to elucidate the effects of alloying and thermal history on the phase equilibrium in Mo-rich alloys.     

Distributed System for Coastal Infrastructure Modeling and Assessment

The client/server computer architecture of the Internet provides an efficient mechanism for implementing effective civil infrastructure monitoring and assessment applications. Systems functionality that is enabled by this important technology includes remote and real-time data acquisition, distributed model execution and control, multiuser access to and monitoring of decision support systems, and efficient systems expansion and maintenance. With the dramatic increase in available infrastructure data and the continued improvement in the reliability and robustness of these technologies, widespread design, implementation, and use of distributed infrastructure modeling systems will become common. This paper describes the design and development of a prototype infrastructure modeling system incorporating these technologies that has recently been implemented to help decision makers manage the coastal infrastructure of the Great Lakes.     

A Coupled Experimental Study and Thermodynamic Modeling of the SiO2-P2O5 System

A coupled key phase diagram experimental study and thermodynamic modeling of the SiO₂-P₂O₅ system was conducted. Equilibration and quenching experiments using sealed Pt crucibles were performed in the SiO₂-rich region to resolve inconsistencies found in the literature data about the SiO₂ liquidus. Based on new experimental data and all available and reliable phase diagram and thermodynamic data, the thermodynamic optimization of the SiO₂-P₂O₅ system was carried out to obtain a set of thermodynamic equations for liquid and solid phases in the system. The liquidus slope of SiO₂ indicates that P₂O₅ in the SiO₂-rich liquid exists mainly in the form of P₂O₇ ^4? instead of PO₄ ^3?. Thermodynamic properties of the liquid solution can be predicted from the Gibbs energy of the liquid phase.     

热力学模拟计算软件FactSage及其应用

介绍了当今最具代表性的Thermo-Calc和FactSage热力学计算软件. 将FactSage应用于金川镍闪速熔炼过程的复杂多元多相平衡计算, 表明金川镍闪速熔炼炉渣中铜含量的理论计算值(0.043%～0.060%)远小于实际值(0.28%～0.30%), 进一步降低渣中含铜量热力学上是可能的;利用FactSage计算了一系列不同成分的Fe-B合金在实际应用条件下的相组成和相含量及其变化规律, 综合考虑各合金的工艺性能、力学性能和耐锌液腐蚀性能, 用优选方案制备的成分为7.01%B, 5.05%B和3.31%B, 相组成为α-Fe Fe2B的Fe-B二元合金可较好地满足抗液锌腐蚀结构材料的综合性能要求.     

Gibbs Energy Modeling of the Cu-S Liquid Phase: Completion of the Thermodynamic Calculation of the Cu-S System

Metallurgical and Materials Transactions B - A thorough review and critical evaluation of all experimental sulfur potential and phase diagram data available from the literature has been made for...