NEW METHODS FOR CALCULATING ACTIVITIES OF COMPONENTS FROM PHASE DIAGRAMS IN BINARY PERITECTIC SYSTEMS

ＮＥＷＭＥＴＨＯＤＳＦＯＲＣＡＬＣＵＬＡＴＩＮＧＡＣＴＩＶＩＴＩＥＳＯＦＣＯＭＰＯＮＥＮＴＳＦＲＯＭＰＨＡＳＥＤＩＡＧＲＡＭＳＩＮＢＩＮＡＲＹＰＥＲＩＴＥＣＴＩＣＳＹＳＴＥＭＳ①ＺｈａｎｇＹｏｎｇｊｕｎＨｕｎａｎＳｕｐｅｒｉｏｒＴｅｃｈＭａｔｅｒｉ...

Relationship between the types of binary alloy phase diagrams of Ⅷ and IB group elements and the Mendeleev numbers

The relationship between the types of binary alloy phase diagramsof VIII and Ib group elements and the Men- deleev numbers wasdiscussed for the first time using the VIII and IB group elements assolvent metals (A) and the other elements as solute metals (B),basesd on their alloy phase diagram types. The Mendeleev numbers ofthe solvent metals and the solute metals were expressed as M_A andM_B, respectively. A two-dimension map of M_A/M_B was drawn. It isindi- cated that there is an oblique line in the map, which dividesthe binary alloy phase diagram types of solvent metals into twosymmetry parts, the phase diagram types of the other elements withsolvent metals located at the above or down of the line respectively,while on the line, △M = 0.

Prediction of Heat of Fusion of Rare Earth Compounds from Binary Phase Diagrams

Based on the thermodynamical principle the new formula for calculation of heat of fusion and its error have been derived from binary phase diagrams which could be classified to eutectic,solid solution,degenerate eutectic and involving a compound phase diagram and so on.Using these formulae heats of fusion of some rare earth ox- ides have been predicted.

Estimation of Thermodynamic Properties from Binary Phase Diagram

The general relationship between binary phase diagrams and the thermodynamic properties was system- atically derived without any assumption.A procedure was presented to estimate the thermodynamic proper- ties from the binary phase diagrams.

ASSESSMENT AND OPTIMIZATION OF THE PHASE DIAGRAMS AND THERMODYNAMIC DATA OF SOME BINARY SYSTEMS CONTAINING PRASEODYMIUM CHLORIDES

In this paper a critical assessment and optimization of the phase diagrams and thermodynamic properties of the PrCl_3-MCl(M=Li,Na)and PrCl_3-MCl_2(M=Mg,Ca,Sr,Ba) binary systems have been per- formed.The assessed and optimized binary phase diagrams and thermodynamic data with self consistency are a better basis for constructing multicomponent phase diagrams.

The Collins Model and the Eutectic—Type and the Peritectic—Type Phase Diagrams

From the Gibbs free energy and the equations of two-phase equilibrium curves of the two-dimensionalbinary system which has the Lennard-Jones potential, using the Collins model, the eutectic-type phase diagram and theperitectic-type phase diagram of the binary system are obtained, whose results are quite similar to the behavior of thethree-dimensional (3D) substances.

MOLTEN SALT PHASE DIAGRAMS CALCULATION USING ARTIFICIAL NEURAL NETWORK OR PATTERN RECOGNITION-BOND PARAMETERS

ＭＯＬＴＥＮＳＡＬＴＰＨＡＳＥＤＩＡＧＲＡＭＳＣＡＬＣＵＬＡＴＩＯＮＵＳＩＮＧＡＲＴＩＦＩＣＩＡＬＮＥＵＲＡＬＮＥＴＷＯＲＫＯＲＰＡＴＴＥＲＮＲＥＣＯＧＮＩＴＩＯＮＢＯＮＤＰＡＲＡＭＥＴＥＲＳ①Ｐａｒｔ１．Ｔｈｅｐｒｅｄｉｃｔｉｏｎｏｆｔｈｅｐｈａ...

Construction of Solidus Lines of Binary Metal Systems Having a Low Solubility of Components in the Solid Phase

The paper presents the calculation results on the construction of solidus lines of phase diagrams for some binary metal systems based on cadmium, zinc and tellurium. The investigations have been carried out using the phase equilibrium thermodynamics and known liquidus lines. By the calculation method the solidus lines of phase diagrams of the Cd-Na, Cd-Tl, Te-Ga, Te-As, Te-Cu and Zn-Sn systems were constructed in the temperature range from the base component melting point to the eutectic transformation temperature. In the Cd-Tl, Te-As, Te-Cu and Zn-Sn systems a retrograde solubility of the second component in the solid phase was observed. The temperature and maximum solubility values at the retrograde behavior of solidus lines, as well as, the limiting solubility values of components at eutectic transformation in the systems based on Cd, Zn and Te were determined.

A Future Life of Binary Phase Diagrams

The article raises the question of what to do with one of the main achievements of metal science in recent years—binary phase diagrams. These diagrams play a key role in the science of alloys and therefore their reliability must be complete. However, the discovery of the “ordering-separation” phase transition, which showed that in binary alloys at certain temperatures the sign of the chemical interatomic interaction changes (and, consequently, the microstructure changes), forces us to reconsider our ideas about those areas. Currently, these areas are designated on diagrams as areas of a “disordered solid solution.” This article proposes, using transmission electron microscopy, to study all the so-called solid solution regions, and apply the results obtained to the studied regions of the phase diagram.

Investigating Stability Properties for Transition Metal Carbonate Precursors Using Universal Cluster Expansion Technique(UNCLE)as Cathodes for Li-Ion Batteries

The universal cluster expansion technique was used in this study to determine the binary phase diagrams for the transition metal carbonate precursors MCO3(M:Mn,Ni,Co).The use of mixed cathode materials in lithium-ion batteries such as NMC(Ni,Mn and Co)formulations,is a strategic approach to optimize performance,enhance safety and address cost and environmental considerations in the rapidly evolving field of energy storage.This study focuses on the cost issue related to lithium ion batteries by investigating the manganese rich NMC since manganese is more abundant and cost-effective.We doped MnCO3 with nickel and doped MnCO3 with cobalt then ran cluster expansion calculations to generate binary phases.The binary phase diagrams generated indicated that doping MnCO3 with nickel favours the Mn-rich side,while doping MnCO3 with cobalt favours 50%Mn-rich and 50%Co-rich.We further extracted the most stable structures from both binary diagrams and determined their electronic,mechanical and vibrational stabilities using DFT(density functional theory)calculations within the LDA(local gradient approximation)with Hubbard parameter(U).The electronic properties revealed that both materials are semiconductors due to their narrow energy band gap obtained while the mechanical properties showed that structures are mechanically stable since their necessary conditions for trigonal and triclinic systems were satisfied.

First Binary Mixture Ionic Liquids Containing EMIMBr and IM

A new series of binary mixture ionic liquids comprising 1-ethyl-3-methylimidozalium bromide (EMIMBr) and imidazole (IM) have been synthesized. The melting points of the ionic liquids vary with the different content of IM while they still keep satisfactory conductivity and viscosity. According to the analysis of its phase diagram, the eutectic point is about 16.5C with the mass percentage of IM 29%.

Thermodynamic assessment of the Ni-Sb binary system

The Ni-Sb binary alloy system was thermodynamically assessed using CALPHAD approach in this article. Excess Gibbs energies of solution phases, liquid and fcc phases, were formulated using the Redlich-Kister expression. The intermediate phases were modeled by the sublattice model with （Ni,Va）0.5（Ni,Sb）0.25（Ni）0.25 for Ni3Sb_HT phase and （Ni,Va）0.3333（Sb）0.3333（Ni,Va）0.3333 for NiSb phase. The other phases including Ni3Sb, Ni7Sb3, and NiSb2 were treated as stoichiometric compound owing to their narrow composition ranges. Based on the reported thermodynamic properties and phase diagram data, the thermodynamic parameters of these phases were optimized, and the obtained values can reproduce the available experimental data well.

Thermodynamic assessment of Mg-Ga binary system

In order to obtain the thermodynamic description of the Mg-Ga binary system,the thermodynamic assessment of the system was carried out using the CALPHAD method through Thermo-calc software package based on the evaluation of all available experimental data from the published literature.The solution phases,including liquid,hcp(Mg) and orthorhombic(Ga),were described by the substitutional solution model,of which the excess Gibbs energies were expressed with the Redlich-Kister polynomial.Meanwhile,all intermetallic compounds,Mg5Ga2,Mg2Ga,MgGa,MgGa2 and Mg2Ga5,were modeled as stoichiometric compounds.A set of self-consistent thermodynamic parameters formulating the Gibbs energies of various phases in the Mg-Ga binary system were obtained finally.The much better agreement is achieved between the calculated results and the reported experimental data.

Thermodynamic modeling of the Ge-La binary system

The Ge-La binary system was critically assessed by means of the calculation of phase diagram （CALPHAD） technique. The asso- ciate model was used for the liquid phase containing the constituent species Ge, La, Ge3La5, and Ge1.7La. The terminal solid solution diamond-（Ge） with a small solubility of La was described using the substitutional model, in which the excess Gibbs energy was formulated with the Redlich-Kister equation. The compounds with homogeneity ranges, μ（Gel.7La）, β（Ge1.7La）, and （GeLa）, were modeled using two sublatrices asα（Ge,La）l.7La, β（Ge,La）l.7La, and （Ge,La）（Ge,La）, respectively. The intermediate phases with no solubility ranges, Ge4Las, GeaLa4, Ge3Las, and GeLa3, were treated as stoichiometric compounds. The three allotropic modifications of La, dhcp-La, fcc-La, and bcc-La, were kept as pure element phases since no solubility of Ge in La was reported. A set of self-consistent thermodynamic parameters of the Ge-La binary system was obtained. The calculation results agree well with the available experimental data from literatures.

Analysis of Phased-Mission System Reliability and Importance with Imperfect Coverage

Accounting for static phased-mission systems (PMS) and imperfect coverage (IPC), generalized and integrated algorithm (GPMS-CPR) implemented a synthesis of several approaches into a single methodology whose advantages were in the low computational complexity, broad applicability, and easy implementation. The approach is extended into analysis of each phase in the whole mission. Based on Fussell-Vesely importance measure, a simple and efficient importance measure is presented to analyze component’s importance of phased-mission systems considering imperfect coverage.

TNBA/TNAZ最低共熔物的制备及性能

采用静电喷雾方法制备了2,4,6-三硝基-3-溴苯甲醚(TNBA)与1,3,3-三硝基氮杂环丁烷(TNAZ)不同质量比的低共熔物。根据低共熔物的差示扫描量热(DSC)曲线绘制了二元温度-组成(T-X)、熔融焓-组成(H-X)相图,从而得到最低共熔物的质量比。采用扫描电镜(SEM)、能量色散光谱(EDS)、高效液相色谱(HPLC)、X射线粉末衍射(XRD)、红外光谱(IR)、X射线光电子能谱(XPS)、DSC和热重-质谱联用(TG-MS)等方法对最低共熔物形貌、组分含量、元素分布、晶体结构和热分解性质进行了研究,并对最低共熔物的机械感度、热感度和爆轰性能进行了测试和理论计算。结果表明:TNBA/TNAZ最低共熔物的最佳质量比为60.95∶39.05;其微观形貌无尖锐棱角,组分比例与静电喷雾前一致,表面元素分布均匀,晶体结构与原料基本一致;最低共熔温度为350.18 K,相比原料TNBA、TNAZ降低了22.72 K和24.82 K;热分解反应速率常数为0.33 s^(-1),活化焓为60.10 kJ·mol^(-1),活化能为64.44 kJ·mol^(-1),活化吉布斯自由能为135.21 kJ·mol^(-1),活化熵为-143.78 J·(mol·K)^(-1);最低共熔物的撞击感度(H50)为42 cm,摩擦感度(FS)为20%,5 s爆发点温度为558 K;爆轰性能(氧平衡-34.83%,爆热5101.78 kJ·kg^(-1),爆速7598.37 m·s^(-1))介于原料TNBA与TNAZ之间,理论爆轰产物主要为N2、C(d)、CO、CO_(2)及H_(2)O。

Fe-O二元系液相区的试验分析与热力学参数优化

采用无容器激光悬浮加热技术,结合扫描电子显微镜和电子探针显微分析等,对Fe-O二元系液相区进行了相平衡研究。结果表明:Fe-O二元系液相存在溶解度间隙,即存在金属液相与氧化物液相。采用相图计算(CALPHAD)方法并结合试验测得的相平衡信息,对Fe-O二元系液相的热力学参数进行了重新优化,获得了自洽的热力学参数,可为该体系热力学性质的评估提供可靠的数据支撑。

STUDY ON THE PHASE DIAGRAMS FOR Ag-Au, Au-Cu BINARY ALLOYS AT HIGH TEMPERATURE

Ⅰ. INTRODUCTIONThe diagram phase is the important foundation of materials research, and the theoretical description of it is mostly concentrated on the calculation of energy of formation and configurational entropy for alloy. For the latter, the cluster variation method (CVM proposed by Kikuchi in the 1950’s) provides a good approximation model and paves a new way for the theoretical study of phase diagram for alloy. However, most of the

贵金属二元合金相图研究的新进展和展望

对贵金属二元合金相图研究现状及其可靠性进行了全面的分析 ,把贵金属与周期表中各元素的相互作用分成连续固溶体、简单包晶型、简单共晶型、简单偏晶型、生成化合物的复杂体系和在固态和液态都不互溶的 6种类型 ,并把它们放在元素周期表中进行研究后 ,定性总结了它们的若干规律 ;评价了二元相图坐标的热力学表示原理 ;评价了二元相图的半经验计算法和中间相的IUPAC (国际理论化学和应用化学联合会 )和MSIT (国际材料科学组织 )表示法 ,强调半经验的热力学计算法比较成熟 ,而按第一原理的理论计算法尚处在快速发展中 ;

一种基于BDD的多阶段任务系统可靠度新算法

BDD被应用于多阶段任务系统的可靠性分析中,提出了一种新的基于BDD的多阶段任务系统可靠度算法,算法中提出了一次性生成阶段任务系统BDD的快速算法,在生成的BDD的基础上,得到系统的结构函数并计算多阶段任务系统的可靠度,该算法有效解决了马尔可夫链等方法遇到的组合空间爆炸问题,最后结合应用实例,验证了该算法的有效性。