LIQUIDUS OF SYSTEM Ag-Cu-Ge

The diagram of Ag-Cu-Ge system was constructed from the investigation of 13 internal sec-tions by DTA heating as well as cooling curves in an atomsphere of dry N_2 . The phase dia-gram is subdivided into two pseudo-ternary systems shown as Ag-Cu-Cu_3Ge andAg-Cu_3Ge-Ge. Both systems belong to simple eutectic type. The ternary eutectic points liein." E_1, Ag(22.0)-Cu(58.8)-Ge(19.2), 632℃ and E_2 , Ag(44.3)-Cu(29.5)-Ge(26.2), 533℃.The three side binary systems were redetermined.     

Partial phase diagram of Au-Ag-Dy ternary system

On the basis of Au-Ag, Au-Dy and Ag-Dy binary phase diagrams, the 700 ℃ isothermal section of Au-Ag-Dy ternary system（Dye≤35 %, mole fraction） was established by X-ray diffraction analysis, differential thermal analysis and optical microscopy. It is found that there is a long single-phase region, Au（Ag） or Ag（Au）, along the Au-Ag binary isomorphous system on the gold-silver-rich side of the 700 ℃ isothermal section and between the binary compound Au2Dy and Ag2 Dy there is the all proportional solid solution, （Au2 Dy） or （Ag2 Dy）. It is confirmed that the partial 700 ℃ isothermal section consists of six single-phase regions： solid solution Au（Ag） or Ag （Au）, （Au2 Dy） or （Ag2 Dy）, Au6 Dy, Au51 Dy14, Au3 Dy and Ag51 Dy14 ; nine binary-phase regions; （Au2 Dy） ＋ Au （Ag）, Au6Dy＋ Au（Ag）, Au（Ag） ＋Ag51 Dy14 , Ag51 Dy14 ＋ （Au2Dy）, Au3Dy＋（Au2Dy）, Au3Dy＋ Au51 Dy14, Au51 Dy14＋Au6Dy, Au51 Dy14＋Au（Ag） and Au（Ag） ＋Au3Dy; four ternary regions： Ag51 Dy14＋ （Au2Dy）＋ Au （Ag）, （Au2 Dy） ＋ Au（Ag） ＋ Au3 Dy, Au（Ag） ＋ Au3 Dy＋ Au51 Dy14 and Au51 Dy14＋ Au （Ag）＋ Au6 Dy. No new ternary compound is formed in the gold-silver-rich field（Dy≤35 %） of the Au-Ag-Dy ternary system.     

THE LIQUIDUS OF THE TERNARY Ag-Cu-Si ALLOY SYSTEM

1.IntroductionItiswellknownthatAg-Cualloywaswidelyused.Recently,aseriesofternaryalloyscontainingAgandCuwithexcellentpropertiesweredeveloped,forexample,Ag-Cu-Alsystemwithshapememorypropertyll]andAg-Cu-Lasystemamorphousajloyswithgoodductility[21.Inaddition,otherternaryalloyscontainingAgandCuwerealsopaidextensiveattention.ThebillarysystemAg-CuhasbeenwellstudiedandwaseValuatedtwicerecently[3,4].Itwasindicatedthatthissystembelongstoaeutectictypewiththecompositionof39.gat.%Cu 60.lat.%Agandth…     

Investigation on the Phase Diagram of LiCl-KCl-NdCl<Subscript>3</Subscript> Pseudo-Ternary System

The ternary phase diagram of LiCl-KCl-NdCl₃ system has been investigated by differential thermal analysis (DTA), followed by characterization of the coexisting phases in the solid state by x-ray diffraction, in order to understand the interactions in the NdCl₃-LiCl-KCl ternary system. The results of these experiments showed that LiCl and K₂NdCl₅ form a non binary join section. This divides the LiCl-KCl-NdCl₃ system into two quasi-ternary sections, namely (1) LiCl-KCl-K₂NdCl₅ and (2) LiCl-K₂NdCl₅-NdCl₃ systems. Both are simple eutectic ternary phase diagrams. The ternary eutectic temperatures and eutectic compositions are determined to be 316?±?3 °C and 53.9 mol.% LiCl-38.7 mol.% KCl-7.4 mol.% K₂NdCl₅ in the LiCl-KCl-K₂NdCl₅ quasi-ternary section, while the other eutectic temperature and composition are determined to be 376?±?9 °C and 46.2 mol.% LiCl-32.5 mol.% K₂NdCl₅-21.3 mol.% NdCl₃ in the LiCl-K₂NdCl₅-NdCl₃ quasi-ternary section. A quasi-ternary peritectic reaction is observed at 37.7 mol.% LiCl-36.2 mol.% KCl-26.1 mol.% K₂NdCl₅ at 445?±?1°C. The primary and secondary crystallization temperatures for the samples are deduced from the heating runs of DTA traces, and the phases responsible for the various thermal events are ascertained. Isothermal sections at chosen temperatures and polythermal liquidus projection with isothermal contours are drawn over the ternary phase field.     

Low-temperature phase transitions of sodium aluminate solutions

A series of low-temperature phase transitions of sodium aluminate solutions were studied by differential scanning calorimetry (DSC) and Raman spectroscopy. The results indicate that NaOH concentration is a primary impact factor for the binary eutectic point and ice melting temperature of sodium aluminate solutions with low NaOH concentration. In addition, the phase transition process of sodium aluminate solutions with low NaOH concentration from 123.15 to 283.15 K is divided into four steps: non-crystal to crystal, ternary eutectic reaction, binary eutectic reaction and ice melt. The projection phase diagram of NaOH-Al(OH)₃-H₂O system at low temperature was plotted, in which the ternary eutectic temperature for sodium aluminate solutions is 183.15 K.     

Cu-Te-Zr合金铸态组织观察与相分析

采用金相显微镜、场发射扫描电镜和能谱仪,研究了Cu-0.5Te-0.2Zr合金铸态组织与合金中Te、Zr形成的相及其分布。研究表明,Te主要以Cu2Te的形式以长条状或棒状分布在晶界处,此外以少量三元共晶组织的形式存在;Zr的主要存在形式有未溶相、次生相、Cu5Zr二元共晶及三元共晶;未溶相以单质颗粒状存在于晶内,次生相以弥散均匀分布的细小颗粒存在于基体内部,二元共晶组织和少量的三元共晶组织呈不规则块状分布。     

Thermodynamic evaluation of hypereutectic Al–Si (A390) alloy with addition of Mg

This paper presents the thermodynamic evaluation of A390 hypereutectic Al–Si alloy (Al–17% Si–4.5% Cu–0.5% Mg) and alloys up to 10% Mg, using the Factsage® software. Two critical compositions were detected at 4.2% and 7.2% Mg where the temperatures of the liquidus, the start of the binary and of the ternary eutectic reaction are changed. These critical compositions show differences in the formation of Mg₂Si intermetallic particles during the solidification interval. For compositions up to 4.2% Mg, the Mg₂Si intermetallic phase first appears in the ternary eutectic zone. With Mg contents between 4.2% and 7.2%, Mg₂Si particle appears in both the binary and ternary eutectic reactions. Above 7.2% Mg, it solidifies as a primary phase and also during the binary and ternary reactions. The calculated liquid fraction vs. temperature curves also showed a decrease of the eutectic formation temperature (knee point temperature) with the addition of Mg content up to 4.2% Mg. This temperature becomes almost constant up to 10% Mg. The calculation of eutectic formation temperature shows a good agreement with differential scanning calorimetry (DSC) tests.     

含共晶体三、 四元金属熔体作用浓度的计算模型

含共晶体二元金属熔体由２个溶液组成,含共晶体三元熔锍则由３个溶液组成。仿照这两个二、三相熔体的例子,将含共晶体三、四元金属熔体看作由３,４个溶液组成的非均相熔体,并利用含共晶体二元金属熔体的有关热力学参数,针对由同类亚稳态化合物组成的对称型三元系、不同类型亚稳态化合物组成的非对称型三元系及四元系含共晶体金属熔体,制定了相应的作用浓度计算模型。计算的作用浓度与实测活度符合,既证明所制定的模型符合相应金属熔体的结构特性,又证明从含共晶体二元金属熔体和三元熔锍所得到的规律可以应用于含共晶体三、四元金属熔体。     

银钇合金组织研究

采用真空感应炉熔炼制备Ag-9.89%Y二元合金棒,借助金相显微镜、扫描电镜、X射线衍射仪和电子探针研究分析合金的铸态组织特征。结果表明,Ag-Y合金中存在块状和方形环状的初生Ag51Y14化合物相,以初生Ag51Y14相为中心形成向四周发散呈鱼鳞状交替分布的共晶组织。初生Ag51Y14相中的钇含量高于共晶Ag51Y14相。初生Ag51Y14相边界局部直接生长出共晶组织,局部围绕银固溶体组织,环状初生Ag51Y14组织里侧和外侧组织结构相似。共晶组织片层细小,平行生长方向组织呈层片状,垂直生长方向组织呈点状,2种区域含有相同的银和钇含量。     

Computational thermodynamic model for the Mg−Al−Y system

The ternary Mg−Al−Y system was thermodynamically modeled based on the optimization of the binary subsystems Mg−Al, Mg−Y, and Al−Y using the CALPHAD approach. Mg−Al data was taken from the COST507 database, whereas the other two binary systems were reoptimized in this work. The liquid phase was described by a Redlich-Kister polynomial model, and the intermediate solid solutions were described by a sublattice model. Ternary interaction parameters were introduced to enable the best representation of the experimental data while considering the occurrence of the ternary compound Al₄MgY. The constructed database is used to calculate and predict thermodynamic properties, binary phase diagrams of Al−Y and Mg−Y, and liquidus projections of the ternary Mg−Al−Y. The calculated phase diagrams and the thermodynamic properties are in good agreement with the corresponding experimental data from the literature. Sixteen ternary four-phase-equilibria invariant points were predicted in the Mg−Al−Y system: seven ternary eutectic points, eight ternary quasi peritectic points, and one ternary peritectic point. Further, fifteen three-phase-equilibria in variant points were determined: eight saddle points and seven binary eutectic points.     

PHASE DIAGRAM OF SYSTEM NdCl_3-LiCl-KCl

The phase diagram of system NdCl_3-LiCl-KCl has been investigated by DTA.Six surfacescorresponding to the prhnary crystallization of NdCl_3,LiCl,KCl,γ-KCl·NdCl_3,β-3KCl·NdCl_3 and 2KCl·NdCl_3 respectively,eleven univariant lines related to the sec-ondary crystallization,two ternary eutectics E_1(70.5wt-% NdCl_3+8.0wt-% KCl,360℃)and E,(5.0wt-% NdCl_3+ 53.0wt-% KCl,355℃)and one ternary peritectic P(67.0wt-% NdCl_3+10.0wt-% KCl,375℃)were found.It is also chtrified that this studyon the system NdCl_3- KCl differs from previous work in the two transition temperatures:e_1(77.0 wt-% NdCl_3,484℃),e_2(40.0wt-% NdCl_3,620℃),p(70.0wt-%NdCl_3,610℃),3KCl·NdCl_3(690℃)and two reactions:α-3KGl·NdCl_3β-3KGl·NdCl_3 (355℃)β-SKGl·NdCl_3γ-3KCl·NdCl_3 (450℃)The eutectic point e_5(31.0wt-%LiCl,460C)is determined for the pseudobinary system3KCl·NdCl_3—LiCl.     

Thermodynamic evaluation of phase equilibria in the CaCl2-MgCl2-CaF2-MgF2 system

The phase diagram of the CaCl₂-CaF₂-MgCl₂-MgF₂ reciprocal ternary system was calculated thermodynamically from available data on the common-ion binary subsystems and from available data on the CaCl₂-MgF₂ join. This join is very nearly quasibinary and divides the system into two quasiternary systems: the CaCl₂-MgF₂-CaF₂ system with a ternary eutectic calculated at 724 +-5 °C and the CaC₂-MgF₂-MgCl₂ system with a ternary eutectic calculated at 561 +-5 °C.     

Thermodynamic evaluation of phase equilibria in the CaCl2-MgCl2-CaF2-MgF2 system

The phase diagram of the CaCl₂-CaF₂-MgCl₂-MgF₂ reciprocal ternary system was calculated thermodynamically from available data on the common-ion binary subsystems and from available data on the CaCl₂-MgF₂ join. This join is very nearly quasibinary and divides the system into two quasiternary systems: the CaCl₂-MgF₂-CaF₂ system with a ternary eutectic calculated at 724 +-5 °C and the CaC₂-MgF₂-MgCl₂ system with a ternary eutectic calculated at 561 +-5 °C.     

Experimental study of the ternary system Cd---Te---Zn

The ternary system Cd---Zn---Te has been studied by differential thermal analysis, differential scanning calorimetry and X-ray powder diffraction. A solid solution is observed between CdTe and ZnTe. At low temperature this quasi-binary section exhibits a miscibility gap. The liquid-liquid miscibility gap induced by the binary monotectic reaction extends within the ternary system and its boundary has been determined. The only ternary reaction existing in this system is a eutectic reaction at 265 °C and the corresponding composition is located in the very close neighbourhood of the binary eutectic Cd---Zn.     

Thermodynamic study of the phase equilibria in the Sn−Ti−Zn ternary system

The Sn−Ti−Zn ternary phase diagram has been constructed using the CALPHAD technique. The Ti−Zn binary system phase boundaries were determined using differential scanning calorimetry and the solid-liquid diffusion couples method. In addition, the formation energy of some stoichiometric compounds was obtained using first-principle band energy calculations. For the ternary system, some alloys were prepared by equilibration at 600 or 700 °C, and the compositions of the precipitates were analyzed using electron probe microanalysis. Thermodynamic assessment of the Ti−Zn and Sn−Ti−Zn systems was performed based on the experimental information and by adopting reported values of the thermodynamic properties of the Sn−Zn and Sn−Ti binary systems. Microstructural observation showed that Sn₃Ti₅Zn₁₂ exists in the ternary system. Seven types of invariant reaction on the Sn-rich liquidus surface of the ternary system are predicted by the phase diagram calculations. The ternary eutectic point falls at 0,0009 mass% Ti and 8.69 mass% Zn, at T=192.40°C, which is slightly lower than the calculated eutectic point of Sn−Zn binary alloy (T=192.41°C). Based on these results, a nonequilibrium solidification process using the Scheil model was simulated. This paper was presented at the International Symposium on User Aspects of Phase Diagrams, Materials Solutions Conference and Exposition, Columbus, Ohio, 18–20 October, 2004.     

Phase equilibria in Ti–Ni–Pt ternary system

Phase equilibria in Ti–Ni–Pt ternary system have been experimentally determined through diffusion triple technique combined with alloy samples approach. Assisted with electron probe microanalysis (EPMA) and X-ray diffraction (XRD) techniques, isothermal sections at 1073 and 1173 K of this system were constructed and existence of ternary phase Ti₂(Ni,Pt)₃ was confirmed. In addition, binary compounds Ti₃Pt₅ and TiPt_3– were found to be stable at 1073 and 1173 K, and remarkable ternary solubility in some binary compounds was detected, e.g., solubility of Pt in TiNi can be up to about 36% (molar fraction) at 1073 K and 40% (molar fraction) at 1173 K. Furthermore, a ternary invariant transition reaction TiNi₃+Ti₃Pt₅→Ti₂(Ni,Pt)₃+TiPt₃₊ at a temperature between 1073 and 1173 K was deduced.     

Thermodynamic prediction of the composition of Fe-based amorphous alloys

The liquidus univariant lines of the Fe-Nb-B ternary system have been thermodynamically calculated by means of CALPHAD method and Fe-based thermodynamic data. It is found that there are two eutectic reactions in the Fe-rich corner,that is,（1） L（Fe-3Nb-15B） →α＋γ＋ M2B （1430 K）,and （2） L（Fe-10Nb-27B） → FeB ＋ Lc14 ＋ M2B （1575 K）. Moreover,the eutectic points are very close to the compositions with high glass forming ability determined experimentally. This means that it is feasible to design the compositions of multicomponent bulk metallic glasses by looking for the eutectic points in the Fe-Nb-B system by means of thermodynamic calculation.     

无铅锡基钎料合金设计和合金相图及其计算

阐述了无铅钎料合金设计的原则, 讨论了合金相图及其计算在无铅锡基钎料合金设计中的作用. 利用相图计算技术筛选了可能代替Pb-Sn共晶钎料合金的Sn-Zn-In三元(x(Zn)＜0.11, x(In)=0.10～0.14)和Sn-Zn-In-Ag四元(x(Sn)=0.800, x(In)=0.090, x(Zn)=0.075, x(Ag)＜0.049)无铅锡基钎料合金. 初步讨论了用相图计算技术在富Sn四元Sn-Zn-In-Ag无铅钎料合金基础上, 添加Bi, Sb等低熔点金属和微量Ce, La等稀土元素以降低贵金属In和Ag的含量, 进一步提高无铅锡基多元合金钎料的综合性能和性能价格比.     

PHASE DIAGRAM OF TERNARY SYSTEM PrCl_2-CaCl_2-MgCl_2

Three surfaces corresponding to the primary crystallization of PrCl_3,CaCl_2 andMgCl_2 respectively,3 univariant curves related to the secondary crystallization and a ternaryeutectic(44.8 wt-% PrCl_3,31.8 wt-% CaCl_2,546℃)were found in systemPrCl_3-CaCl_2-MgCl_2 by means of DTA.A reaction occurs in this system:L=PrCl_3+CaCl_2+MgCl_2.     

新型高强度压铸Al-Si-Mg-Mn合金组织和性能的演变

研究了新型高强度Al-Si-Mg-Mn合金组织和性能的演变.基于JMatPro相图模拟计算,设计了不同共晶体积分数的Al-Si-Mg-Mn合金成分.结果 表明,新型Al-Si-Mg-Mn合金压铸后(铸态)的抗拉强度可达230～310MPa,屈服强度200～240MPa,伸长率约0.5％.铸态组织中包含α-Al、α-Al...