Thermodynamic assessment of Cu-Cd system

A thermodynamic assessment of the Cu-Cd system has been carried out by CALPHAD technique.The liquid phase, FCC_A1(Cu)and HCP_A3(Cd)terminal phases are described by a simple substitutional model,their excess Gibbs energy is formulated with the Redlich-Kister expression.The system contains four intermediate compounds,includingβ(Cu2Cd),γ(Cu4Cd3), δ(Cu5Cd8)andε(Cu3Cd10).Theδphase is described by a two-sublattice model and the other three intermediate phases are treated as stoichiometric phases.The optimization is carried out in the Thermo-Calc package.A set of self-consistent thermodynamic parameters are obtained.The calculated phase diagram and thermodynamic properties agree well with the available experimental data.     

多元Al合金的热力学和热物理数据库的建立及凝固过程显微组织演变的模拟

介绍了相图热力学及热物理性能数据库的建立方法;综述了国内外学者构筑多元Al合金相图热力学和热物理性能数据库的研究工作。并介绍了使用相场方法,使用热力学和热物理性能数据库模拟多元Al合金凝固时显微组织演变的几个实例。最后展望了新一代热力学和热物理性能数据库建立及凝固过程显微组织演变定量模拟未来的可能发展方向。     

Thermodynamic assessment of Au-Zr system

1　INTRODUCTIONChemicalvapordeposition (CVD)diamondholdsgreatpromiseinsolvingthermalmanagementprobleminhigh performancemulti chipmodules (MCMs) .However ,thismaterialdoespresentsometechnologi calchallenges ,onebeingthedevelopmentofreliablemetallizationsystems[1] .Thedesirablecharacteristicsofametallizationsystemare goodadhesiontothesubstrate ,lowstress ,goodelectricalconductivityandminimalreactionsatsubsequentprocessingtempera tures (upto 4 0 0℃ ) [2 ] .Goldisusuallychosenasthemetalfor…     

Transformations and phase relations in Nb—Ti—Si ternary system at 1373—1473K

1　ＩＮＴＲＯＤＵＣＴＩＯＮＢｅｃａｕｓｅｏｆｔｈｅｉｒｈｉｇｈｓｔｒｅｎｇｔｈ ,ｇｏｏｄｐｌａｓｔｉｃｉｔｙａｎｄｃｏｒｒｏｓｉｏｎｒｅｓｉｓｔａｎｃｅ ,ｅｓｐｅｃｉａｌｌｙｌｏｗｄｅｎｓｉｔｙａｎｄｅｘｃｅｌｌｅｎｔｆｒａｃｔｕｒｅｔｏｕｇｈｎｅｓｓ ,     

Experimental determination and Re—optimization of Ni—Ta binary system

1　ＩＮＴＲＯＤＵＣＴＩＯＮＮｉ Ｔａｂｉｎａｒｙａｌｌｏｙｈａｓｂｅｅｎｔｈｅｓｕｂｊｅｃｔｏｆｍｕｃｈｒｅｓｅａｒｃｈｏｗｉｎｇｔｏａｃｏｍｂｉｎａｔｉｏｎｏｆｓｃｉｅｎｔｉｆｉｃａｎｄｔｅｃｈ ｎｏｌｏｇｉｃａｌｉｎｔｅｒｅｓｔ .Ｏｎｏｎｅｈａｎｄ ,ｔ     

THERMODYNAMIC OPTIMIZATION AND CALCULATION OF THE Fe-Pr SYSTEM

Based on the phase diagram of the Fe-Pr system available,the thermodynamic optimization and calcula-tion of the system have been carried out by the least square method.The lattice stabilities of Fe and Pr aredescribed by the expression recommended by SGTE organization.The liquid phase is described by thesubregular solution model.The intermetallic compounds,Fe_(17)Pr_2 and Fe_2Pr,are treated as stoichiometriccompounds.The optimized parameters describing phases in the system are presented.The comparision be-tween the calculated and experimentally determined phase diagram shows that the agreement is generally verygood except for the liquid δ-Fe equilibrium.It is suggested to measure this part of phase diagram again.     

A Study of the Isothermal Section in the W-Fe-Co Ternary System at 1380K

The purpose of the present paper isto determine the composition range ofthe θ intermediate phase and establishthe phase equilibria relation in theW-Fe-Co ternary system.The experimentalresult was compared with the calculationof phase diagrams in Guillermet's work.1.Experimental ProcedureThe diffusion couple specimen usedin this investigation was prepared fromthe tungsten bar (99.96 wt-%),electro-     

ISOTHERMAL SECTION OF THE W-Ni-Cu SYSTEM AT 1017℃

采用扩散偶试样,借助电子探针、X射线衍射等分析方法,测定了W-Ni-Cu三元系1017℃等温截面。在该温度下,W-Ni二元系存在体心四方结构的Ni_4W和正交结构的NiW,没有观察到NiW_2。钨在Ni_4W中的固溶度范围为16.95—20.51at.-％(39.00—44.70wt-％),Cu在Ni_4W中的固溶度范围为0—4.36at.-％(3.40wt-％).钨在γ(Ni)固溶体中的最大固溶度为13.11at.-％ (32.10wt-％).     

Thermodynamic optimization of Mg-Nd system

Based on the reported experimental data,the phase diagram of Mg-Nd binary system was optimized using the CALPHADapproach.Gibbs energies of the disordered BCC_A2 and ordered BCC_B2 phases were modeled with a single expression based on a2-sublattice model.Liquid and terminal solutions,such as dHCP and HCP,were modeled as substitutional solutions.Intermediatephases Mg2Nd,Mg3Nd and Mg41Nd5 were treated as stoichiometric compounds.The optimization was carried out in theThermo-Calc package.A set of thermodynamic parameters is obtained.Calculated phase diagram,enthalpies of formation and Gibbsenergies of formation are in reasonable agreement with the experimental data.     

Determination of isothermal sections of Ni-Cr-Nb ternary system

The isothermal sections of Ni-Cr-Nb ternary system at 1 323 K and 1 423 K were determined by means of diffusion triple and energy spectrum analysis (ESA). By analyzing the diffusion layers in the diffusion couples, the compounds forming in this system were identified. There are three similar compounds found at these two temperatures: Ni3 Nb, NiNb and NbCr2-R, and four similar three-phase regions are found : (Ni) (Cr) Ni3 Nb, Ni3Nb NbCr2-R NiNb, NbCr2-R (Cr) Ni3 Nb, NbCr2-R NiNb (Nb). The results show that no phase transformation happens between these tow temperatures. But the solid solubilities of the binary compounds at 1423 K become bigger than those at 1 323 K, especially the solid solubility of NbCr2-R. No ternary compound is observed.