Liquidus Projection of the B-Fe-U Diagram: The Boron-Rich Corner

The liquidus projection at the boron-rich corner of the B-Fe-U phase diagram is proposed based on powder X-ray diffraction measurements, heating curves, and scanning electron microscopy observations, complemented with both energy dispersive X-ray spectroscopy and electron probe microanalysis. Evidence for six ternary reactions is presented, the corresponding 12 monovariant lines are drawn, and the nature and location of the ternary reactions are given. The ternary compounds existing in this region of the B-Fe-U ternary phase diagram, UFeB₄ and UFe₂B₆, were confirmed to be formed by ternary peritectic reactions, yet UFeB₄ has a considerably larger primary crystallization field, which points to an easier preparation of single crystals of this compound, when compared with UFe₂B₆.     

Liquidus Projection of the B-Fe-U Diagram: The Fe-Rich Corner

The liquidus projection of the Fe-rich corner of the B-Fe-U phase diagram is proposed based on powder X-ray diffraction measurements, differential thermal analysis, and scanning electron microscopy observations complemented by energy dispersive X-ray spectroscopy. The present work demonstrates the existence of 10 ternary reactions together with 18 monovariant lines and establishes their location and approximate temperatures. The ternary compounds existing in this region of the B-Fe-U ternary phase diagram, UFe₃B₂, UFe₄B, and U₂Fe₂₁B₆, were confirmed to form by ternary peritectic reactions, yet UFe₄B and U₂Fe₂₁B₆ have minute primary crystallization fields, indicating a more challenging preparation of single crystals for these compounds when compared with UFe₃B₂.     

The InTe-Sb Phase Diagram

Abstract

A computer program was developed which takes experimental orientation analysis data from the transmission electron microscope and determines the corresponding best fit crystal orientation. This program was used to analyse the relative orientations between pearlitic ferrite and cementite in annealed and as-rolled eutectoid steel in terms of near-coincident site lattice (NCSL) solutions.

The NCSL theory predicted not only the “standard” orientation relationships, i.e. Bagaryatskii and 2nd Petch, but also “non-standard” orientation relationships. Certain observed ferrite/cementite relative orientations showed significant deviations from any NCSL. The explanation of these deviations and of the non-observation of certain low-sigma solutions probably requires the consideration of inter-atomic forces, rather than only the near-coincidence of lattice points.     

Schaeffler-Type Phase Diagram of Ti-Based Alloys

The α(hcp)/β(bcc) phase equilibria of Ti-based multi-component alloys can be described by a Schaeffler-type diagram, where Al and Mo equivalents (Aleq and Moeq) are used. Aleq is thermodynamically defined by the ratio of partial molar free energy changes transfer of one mole of each α forming element and Al from a dilute solution of α to β phases, while Moeq is also deduced by similar thermodynamic quantities of β forming element and Mo. Aleq and Moeq for 40 alloying elements are estimated from the thermodynamic parameters assessed by Kaufman and Murray. It is shown that three types of Ti alloys, i.e., α and near α, α+β, and β alloys, can be exactly classified using Aleq and Moeq. The Ms and β transus temperatures can also be predicted by Aleq and Moeq. The proposed Aleq and Moeq are very useful for alloy design, heat treatment, and microstructural evolution of Ti-based alloys.

     

Partial Redetermination of the Fe-W Phase Diagram

The objective of the current study is to perform a careful investigation of the (Fe) and (W) solvus and of the intermetallic compounds in the Fe-W system as it could have a significant impact on higher-order systems based on this binary system. Two key alloys, Fe-14 at. pct W and Fe-50 at. pct W, and a diffusion couple were synthesized based on the literature. They were studied by long time annealing experiments with a selected heat treatment route, X-Ray diffraction analysis, and electron microprobe analysis with a careful control of impurity levels of C, Si, and O. The two intermetallic phases μ-Fe₇W₆ and λ-Fe₂W are characterized and the composition range of the μ-Fe₇W₆ phase is specified. The phase previously reported as FeW is most probably a ternary carbide with low carbon content. An accurate determination of the solubility of W in αFe and of Fe in αW is presented.     

分层体系二元相图的热力学分析

出现分层曲线的二元相图,可以按临界点将曲线分为两部分,l_α和l_β;对应分层的两溶液相α,β的热力学性质有4个:IIE(α),S~E(α),IIE(β),SE(β)。加上相图中两温度-组成曲线l_α和l_β共6个量,经过热力学分析可以给出这6个量间的关系:假设这6个量间的任意4个已知,可以将另外2个量计算出来。因此,在一些条件下,可以给出有价值的结论或公式。     

Phase Diagram of the Scandium - Tin System

We have used differential thermal analysis, metallographic analysis, and x-ray phase analysis to study cast alloys of scandium with tin. We have used the data to plot the phase diagram for the scandium - tin system in the 0–60 at.% tin region.     

Phase Diagram of the Ni ― Os System

Metallography, DTA, x-ray, and electron-probe microanalysis methods have been applied to alloys with four compositions in the cast and annealed states. A phase diagram has been constructed for the entire concentration range on the basis of these data together with published ones. The diagram is of peritectic type, and the peritectic temperature is 1500°C. The mutual solubilities of the components at that temperature are 13.3 at.% osmium in nickel and 13 at. % nickel in osmium. The solubility of osmium in nickel falls to 9.2 at. % when the temperature is reduced to 1200°C.     

EuCl3-BaCl2二元系相图的研究

利用差热分析法研究了EuCl3-BaCl2二元系相图,发现该体系有一个固液同组成化合物3EuCl3·2BaCl2,体系相变点为950℃,EuCl360%(摩尔分数);一个异份熔化化合物2EuCl3·3BaCl2,转熔点为630℃,EuCl3 43.6%(摩尔分数);2个低共熔点分别为320℃,EuCl3 51%(摩尔分数)和330℃,EuCl3 79%(摩尔分数).同时探讨了相图的某些规律.     

EuCl3-NdCl3二元系相图的研究

利用DTA研究了EuCl3-NdCl3二元系相图,该体系有一个同分熔化化合物2EuCl3·3NdCl3,该化合物在635℃熔化,其成分为NdCl3,含量为60.0%(摩尔分数,下同),体系的2个低共熔点分别为462℃(NdCl3含量为33.2%)和582℃(NdCl3含量为71.4%).     

FeO-V2O5二元相图的研究

对FeOV2O5二元系通过XRD试验进行物相分析,理论计算中间化合物的热力学参数,并建立了溶液热力学模型,结合FACT软件计算绘制出FeO-V2O5二元系相图,通过DSC试验和XRD试验验证相图.此体系相图由三个共晶反应组成并且生成两种中间化合物反式尖晶石Fe2VO4和钒酸铁FeVO4,试验的结果对理论计算出的相图有很...     

用特征晶体模型计算Ta-W相图

介绍用特征晶体模型描述合金热力学的基本原理和方法。对Ta—W相图进行了优化和计算，选择描述有序和无序Ta-W合金相吉布斯自由能表达式，并确定其中的参数。计算的相图与前人的计算的一致。讨论有序Ta—W合金的热力学，并说明无序Ta-W固溶体比有序的金属间化合物更稳定。     

用特征晶体模型研究Au-Cu热力学性质

基于特征晶体模型，用最小二乘法拟合了Au-Cu热力学相互作用方程参数。在此基础上研究了Au-Cu合金的生成热、组元活度和Gibbs自由能随温度的变化曲线，确定了体系固液发生成分不变相变点的温度，计算结果与实验数据一致。评估了Au-Cu体系相图，其主要特征与CALPHAD评估结果和实验信息一致。     

作为材料设计基础的相图研究

介绍了现代材料设计与相图研究之间的关系，强调了计算相图的出现使相图研究成为材料的设计的一部分，相图计算程序系统的另一重要功能是评估和优化热力学参数，以双相纳米材料、宽滞后形状记忆合金、钕铁硼永磁合金、钛铝金属间化合物和低温用钢的研究开发为例，说明了相图研究在材料设计上的重要作用。     

Experimental Study on the Phase Diagram of the Fe-O-S System

The phase equilibria information on the Fe-O-S system holds high importance for industrial metallurgical processes. The phase diagram of the Fe-O-S system in equilibrium with metallic iron and wustite has been constructed at temperatures between 1223 K and 1473 K (950 °C and 1200 °C). In addition, the eutectic temperature of the system has been determined to range between 1188 K and 1193 K (915 °C and 920 °C). High-temperature equilibration/quenching/electron probe X-ray microanalysis technique has been used to measure the compositions of the phases in equilibrium in the system.     

贮热材料多元醇PE-TAM二元体系相图

利用差热分析(DTA)及变温红外光谱技术测定了季戊四醇-氨基异丁基三醇(PETAM)二元体系的相图。研究表明,在该相图中存在两个低共熔点和一个转晶点,多元醇分子在低温时的有序和高温时的无序是影响二元体系不同相间互溶度的重要因素。     

CaCl2-CaF2-CaO三元体系的相图计算

基于Calphad方法,首先对CaCl2-CaO、CaCl2-CaF2和CaO-CaF2体系进行了系统的热力学评估和优化。采用置换溶液模型来描述液相和固溶体相的吉布斯自由能,所有中间相因其固溶区域十分有限而近似处理成准化学计量比化合物,且其自由能依据Neumann-Kopp规则定义。其次,利用Muggianu溶液几何模型将优化获得的所有子二元系的模型参数扩展至CaCl2-CaO-CaF2三元体系。最后,对共晶点进行配样和差示扫描量热法（DSC）测试,通过引入三元交互参数使计算结果与试验数据一致,从而获得了一套自洽的CaCl2-CaO-CaF2三元体系热力学数据库。     

Experimental Investigation and Thermodynamic Calculations of the Bi-Ge-Sb Phase Diagram

A phase diagram of the Bi-Ge-Sb ternary system was investigated experimentally by differential thermal analysis (DTA), scanning electron microscopy with energy-dispersive X-ray spectroscopy (SEM-EDS), and X-ray powder diffraction (XRD) methods and theoretically by the CALPHAD method. The liquidus projection; invariant equilibria; and three vertical sections, Sb-Bi_0.5Ge_0.5, Ge-Bi_0.5Sb_0.5, and Bi-Ge_0.5Sb_0.5, as well as isothermal sections at 773 K and 373 K (500 °C and 100 °C), were predicted using optimized thermodynamic parameters for constitutive binary systems from the literature. In addition, phase transition temperatures of the selected samples with compositions along calculated isopleths were experimentally determined using DTA. Predicted isothermal sections at 773 K and 373 K (500 °C and 100 °C) were compared with the results of the SEM-EDS and XRD analysis from this work. In both cases, good agreement between the extrapolated phase diagram and experimental results was obtained. Alloys from the three studied vertical sections were additionally analyzed using the Brinell hardness test.     

Experimental and Calculated Ag + Au + Ge Phase Diagram

The investigation of the equilibrium phase diagram of the Ag + Au + Ge system has been carried out by the following ways: (a) the location of equilibrium surfaces was determined on the whole composition range by high temperature isoperibolic calorimetry and differential thermal analysis; (b) the equilibrium temperatures of the ternary system were calculated from the equilibrium temperatures and the thermodynamic functions referring to the three limiting binary alloys Ag + Au, Ag + Ge, Au + Ge. A satisfactory agreement was found between the calculated liquidus and the one obtained by calorimetry and thermal analysis. In the course of a systematic thermodynamic investigation of ternary alloys based on gold, silver, and a IV b metal, the three systems Ag + Au + Si, Ag + Au + Ge, and Ag + Au + Sn were examined; the molar enthalpies of formation of the liquid mixtures were obtained on the one hand and the equilibrium phase diagrams on the other.^1,2,3 This paper focuses on the latter topics for the ternary alloys Ag + Au + Ge; a comparison is carried out between the equilibrium temperatures measured by differential thermal analysis at the laboratory S.E.T.T. in Marseille and those calculated at the Royal Institute of Technology in Stockholm. This calculation is based on the thermodynamic data published for the limiting binary systems and also on the ternary enthalpies measured by calorimetry at very high temperature.