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Phase equilibria in Al–Ni–Sc ternary system have been measured through alloy sampling. According to the results from electron probe microanalysis and X-ray diffraction techniques, isothermal sections of Al–Ni–Sc ternary system at 1173 K and 1273 K were constructed, where four new ternary phases, τ7 (Ni2Al5Sc), τ8 (Ni2Al4Sc), τ9 (NiAl2Sc3) and τ10 (NiAlSc5), were detected along with the formerly reported ternary compounds, τ1 (NiAlSc), τ2 (Ni2AlSc) and τ5 (NiAl2Sc). The existence of τ3 (Ni7Al16Sc6), τ4 (NiAl4Sc) and τ6 (Ni3Al9Sc) reported previously in the literature was not confirmed in this work. And τ1 shows large composition range at 1173 K and 1273 K.

Luminescent materials were of vital importance in the display, lighting, and biomedical fields. Exploration of novel inorganic host materials and groping for novel color-tunable phosphor materials with good thermal stability is still a major challenge for the quality-improvement of FLs and LEDs. In the present work, a new magnesium indium phosphate, Mg3In4P6O24 (MIP), was successfully synthesized by conventional high-temperature solid-state reaction and was structurally characterized by powder X-ray diffraction analysis, in which magnesium and indium atoms co-occupy four metal cation sites, coordinating with adjacent oxygen atoms forming distorted MO5 and MO6 polyhedra. The VUV-UV excited luminescence properties of a series of Eu3+/Tb3+ doped MIP phosphors were investigated, with the temperature-dependence of photoluminescence and relative mechanism analyzed. Under the excitation of 254 nm, the MIP: EuxTby phosphors can generate bright color-tunable green-yellow-red light by changing the doping concentration. In addition, the color of emission can also be adjusted by altering the excitation wavelength for a very phosphor, MIP: Eu0.01Tb0.05. As an interesting discovery, the plot of integrated dominant emission intensities of Eu and Tb in phosphor MIP: Eu0.01Tb0.05 versus excitation wavelength exhibits analogical profile with the excitation spectra of Eu3+/Tb3+ single-doped MIP phosphor. Moreover, the representative phosphor MIP: Eu0.01Tb0.05 shows favorable thermal stability. Present work indicates that Mg3In4P6O24 is a promising host material for the fabrication of new phosphors.

Phase relations in Cu–Ti–Hf ternary system have been studied by diffusion triple technique supplemented with typical alloy sampling method. Based on results from electron-probe microscopy analysis and X-ray diffraction, isothermal sections of the Cu–Ti–Hf system at 800 and 700 °C were established, which consist of ten and nine three-phase regions, respectively. It is observed that Ti can completely substitute Hf in the CuHf2 phase, indicating formation of a continuous solid solution Cu(Ti,Hf)2. Hf can substitute about 20% Ti in the phase CuTi, while solubility of Ti in Cu10Hf7 and Cu51Hf14 phases reaches to 14 and 11 at.% at 800 °C, respectively. The Cu8Hf3 phase in existence at 800 °C was proved to be unstable at 700 °C. In addition, the elastic modulus and hardness of solid solution Cu(Ti,Hf)2 were determined by using nano-indentation techniques.

As a typical system in the family of heat-resistant aluminum alloys, the Al-Sc-Zr ternary system was thermodynamically studied by experimentation and theoretical calculation. Employing the scanning electron microscopy/energy dispersive X-ray spectroscopy and X-ray diffraction, the isothermal section at 873 K was determined with equilibrated alloys. Two stable ternary compounds Al 75 Sc 16 Zr 9 and Al 75 Sc 10 Zr 15 were newly discovered. By means of the differential scanning calorimetry, phase transformation temperatures of selected samples were obtained. In addition, the as-cast microstructure of individual alloys was observed to identify the primary crystallization phase during solidification. Based on the experimental information mentioned above, the Al-Sc-Zr system was thermodynamically optimized combining the first-principles calculation and the CALPHAD method, with the constituent binary system Sc-Zr optimized for the first time. Using the thermodynamic parameters obtained in this work, the isothermal section, vertical section and liquidus projection were all calculated and then compared with available experimental data, most of which could be accounted for satisfactorily.

Using first-principles calculations, site occupancy behaviors of transition elements in C15 NbCr2 Laves phase are systematically investigated. Elements Y, Sc, Zr, Hf, Cd, Ta, Ti and Ag prefer to occupy the Nb site, and elements Zn, Pt, Re, Tc, Ir, V, Os, Rh, Ru, Ni, Co, Mn, Fe and Cu favor to occupy the Cr site; whereas elements Mo, W, Pd and Au have weak site preference for Cr or Nb site. The present calculations agree well with the available experimental and previously calculated results. It was found that the site occupancy behavior of transition elements in NbCr2 is mainly affected by the radii of transition elements. The present calculations also propose the correlation between the site preference energy and radii of transition elements.

Phase equilibria in Ti–Al–Mo ternary system are of fundamental importance to better acquire the phase-forming regulation of TiAl-based alloys. In this paper, phase relations in this system have been investigated with Ti–TiAl–Mo diffusion triples combined with key equilibrated alloys. Five isothermal sections of the Ti–Al–Mo ternary system at 1473, 1373, 1273, 1173, and 1073 K were experimentally determined by means of electron probe microanalysis, scanning electron microscope, and X-ray diffraction. The TiAl and TiAl3 phases show wide ternary composition ranges, while the solubility of Mo in the Ti3Al and αTi phases is relatively limited. The solubility of Al in the β(Ti, Mo) phase decreases from 49.0 at.% at 1473 K to 39.9 at.% at 1073 K while that of Ti in the AlMo3 phase decreases from 25.4 at.% at 1473 K to 20.8 at.% at 1073 K. Moreover, the ternary compound σ forms at a temperature between 1423 and 1373 K through a peritectoid reaction β(Ti, Mo) + AlMo3 → σ. A peri-eutectoid invariant reaction β(Ti, Mo) + AlMo3 → σ + TiAl3 at 1373–1273 K was further deduced and the existence of another invariant reaction β(Ti, Mo) + TiAl3 → σ + TiAl at a temperature between 1273 and 1173 K was also confirmed. The established phase equilibria of the Ti–Al–Mo ternary system may provide essential data required for the construction of reliable thermodynamic assessment of the Ti–Al–Mo system.

Isothermal sections at 900, 950 and 1000 °C relating to the borate Ba 3 InB 9 O 18 at BO 1.5 -rich corner in the BO 1.5 –BaO–InO 1.5 system were measured with EPMA and XRD, especially the thermal stability of Ba 3 InB 9 O 18 was studied through melting and quenching method. Results showed that isothermal section at 900 °C contains six two-phase regions and six three-phase regions, while isothermal section at 950 and 1000 °C contains three two-phase regions and three three-phase regions. In addition, Ba 3 InB 9 O 18 melts incongruently into InBO 3 and liquid at ∼1025 °C. Breaking of Ba–O bounds in Ba 3 InB 9 O 18 is the trigger of phase transition. Based on the established isothermal sections, primary crystal region of Ba 3 InB 9 O 18 was determined, which will be benefit to designing composition and process for crystal growth of scintillating material Ba 3 InB 9 O 18 .

Novel CaInBO4: xEu(3+) phosphors were synthesized by solid-state reaction method. Their luminescent properties were characterized mainly by UV-visible PLE, PL, VUV, Decay lifetime, and TG-DTA. The excitation and emission spectra indicate that these phosphors can be effectively excited by ultraviolet about similar to 254 nm and exhibit red emission centered at similar to 613 nm attributed to D-5(0)-> F-7(2) transition of Eu3+. Optimum Eu3+ concentration of this phosphor is around 9 mol%. The effect of Al3+/Gd3+ and Ba2+/Sr2+ co-doped CaInBO4: Eu phosphor have been investigated, and the concentration dependence of the emission intensity shows that the optimum doping concentrations of Al3+ and Ba2+ are 3 mol% and 6 mol %, respectively. The UV-vis diffuse reflectance spectra indicate that these phosphors have wide transparent region and the incorporation of Al3+ ions and Ba2+ ions is in favor of light absorption for CIBO: Eu phosphor. The band gaps for these samples were obtained from diffuse reflection spectra, and the excitation wavelengths of phosphors were modified by adjusting their band gaps. According to their decay curves, the calculated lifetime of (Ca1-z, Ba/Sr-z) (In1-x-y, Al/Gd-y) BO4: xEu(3+) phosphors are all shorter than 2 ms. The chromaticity diagram shows that these phosphors can emit red light. The TG-DTA data presents that these phosphors have good thermal stability below 1100 degrees C. The present work suggests that these novel phosphors have potential applications for fluorescent lamps. (C) 2015 Elsevier B.V. All rights reserved.

Ruthenium addition was found to be beneficial in inhibiting the formation of the detrimental topologically closed-packed (TCP) phases in Ni-based single crystal superalloys; thus, the Ni–Cr–Ru phase stability is very valuable for better understanding of the constitutional effects of Ru in multicomponent Ni-base superalloys. Four isothermal sections of the Ni–Cr–Ru system at 800 °C, 900 °C, 1000 °C and 1200 °C were constructed from results obtained from diffusion multiples using scanning electron microscopy (SEM) and electron probe microanalysis (EPMA). The measured phase equilibria together with prior experimental results were used to optimize a CALPHAD thermodynamic description of the Ni–Cr–Ru ternary system using thermodynamic parameters of the Ni–Cr and Ni–Ru systems published in the literature and modified Cr–Ru parameters from the current study. The intermetallic compound sigma phase in the Cr–Ru system was described with a simplified two-sublattice model, (Cr,Ru) 20 (Cr,Ru) 10 , by taking into account future extension of the model into higher order systems. Comparison between the calculated results and the experimental measurements was made to demonstrate the reliability of the current thermodynamic parameters for the Ni–Cr–Ru system. For easy implementation of the thermodynamic parameters into some existing thermodynamic databases, a version of the thermodynamic description of the Ni–Cr–Ru system with an older sublattice model, (Cr,Ni,Ru) 10 (Cr) 4 (Cr,Ni,Ru) 16 , for the sigma phase was also developed.

Phase equilibria in the Cu–Ni–Zr ternary system have been measured through alloy sampling combined with diffusion couple approach. According to the phase relations identified with electron probe microanalysis and X-ray diffraction techniques, isothermal sections at both 1073 and 1293 K were constructed. It is evident that remarkable ternary solubility occurs in almost all binary intermetallic phases at both temperatures. The formerly reported ternary compounds T1 (Cu20–40Ni40–60Zr20) and T2 (Cu20–25Ni60–65Zr15) were not verified in this work. No other ternary compound was detected. In addition, continuous dissolution between Cu10Zr7 and Ni10Zr7 at 1073 K was observed.

The Al–Dy–Zr ternary system has been experimentally studied and thermodynamically assessed to contribute to the development of novel heat-resistant aluminum alloys. Using equilibrated alloys, the isothermal section of this ternary system at 873 K has been established by means of scanning electron microscopy/energy-dispersive X-ray spectroscopy (SEM/EDX) and X-ray diffraction (XRD). Experimental information on vertical sections was obtained by performing differential scanning calorimetry (DSC) analysis on selected annealed samples and that on liquidus projection was extracted from the as-cast samples by observing the primary crystallization phases. In addition, the first-principles method was employed to calculate the enthalpy of formation of metastable compounds involved in the sublattice model. Based on the experimental data and first-principles calculation results in this work, the Al–Dy–Zr system was optimized within the framework of the calculation of phase diagram (CALPHAD) method. Good agreement was found between the experimental data and the thermodynamic calculation results, which indicates that the thermodynamic description developed in this work is reliable.

Subsolidus phase equilibrium of CoO–In 2 O 3 –B 2 O 3 system has been investigated mainly by solid-state reaction and powder X-ray diffraction method. A novel compound Co 2 InBO 5 was found and synthesized for the first time. There are five definite three-phase regions and one solid solution Co 3 − X In X BO 5 (0 X ⩽ 1) in this system under present experimental conditions. This new compound Co 2 InBO 5 and high temperature metastable phase Co 3 BO 5 can form continuous solid solution at all relative concentrations. Crystal structure of three representative Co 3− X In X BO 5 solid solution compounds ( X = 0.4, 0.7, and 1) were refined and determined from X-ray powder diffraction data using Rietveld method. The results showed that the Co 3− X In X BO 5 (0 X ⩽ 1) solid solution crystallized in the orthorhombic space group Pbam (No. 55) with the ludwigite structure type. The lattice parameters ( a , b and c ) of these solid solution compounds increase linearly when In replace Co atom gradually (i.e. with the increase of the value of X ), which obeys the Vegard’s rule. The trigonal BO 3 group in these Co 3− X In X BO 5 solid solution compounds was confirmed by their infrared absorption spectra.

Phase equilibria in Al–Ti–Zr ternary system at 1273 K were experimentally investigated through alloy sampling combined with electron probe micro-analyzer (EPMA) and X-ray diffraction (XRD). No ternary compound was detected. Experimental results show that there is a continuous solid solution β(Ti, Zr) which dissolves up to 25.5 at.% Al, and Ti can substitute Zr in most Al–Zr binary intermediate phases to a certain degree while the maximum solubility of Zr in α 2 (Ti 3 Al) and γ(TiAl) reaches up to 25 at.% and 9 at.%, respectively. The isothermal section consists of 16 single-phase regions, 26 two-phase regions and 14 three-phase regions.

The phase equilibria in the Mg-rich corner of Mg–Zn–Gd ternary system at 673 K were investigated by means of X-ray diffraction (XRD), scanning electron microscopy (SEM) equipped with energy dispersive X-ray spectroscopy (EDS), and electron probe microanalysis (EPMA). Three ternary phases, X-(Mg12ZnGd), W-(Mg3Zn3Gd2) and I-(Mg3Zn6Gd1), have been identified, which are in equilibrium with Mg solid solution. A thermodynamic modeling and optimization of Zn–Gd and Mg–Zn–Gd systems has been carried out for the first time using the CALPHAD method. The sublattice model was used to describe the thermodynamic functions of both solution phases and intermetallic phases presented in these systems. In particular, order/disorder transition between BCC_B2 and BCC_A2 has been taken into account, and their Gibbs energies were expressed with identical function. The thermodynamic database was applied to case studies of experimentally observed microstructures and demonstrated that it is a valuable basis for alloy design.

A thermodynamic description of the Mg–Nd–Zn system was developed by means of the CALPHAD (CALculation of PHAse Diagrams) method. The constituent binary systems Mg–Nd and Nd–Zn were re-optimized based on the experimental phase equilibria and thermodynamic properties available in the literature. Combining with the thermodynamic parameters of the Mg–Zn system cited from the reference, the Mg–Nd–Zn ternary system was evaluated. The Gibbs energies of the solution phases (liquid, BCC_A2, DHCP, HCP_A3 and HCP_Zn) were described by the subregular solution model with the Redlich–Kister polynomial function, and those of the stoichiometric compounds, Nd2Zn17, NdZn11_H, NdZn11_L, Nd3Zn22, Nd13Zn58, Nd3Zn11, NdZn3, NdZn2 and Mg2Nd, were described by the sublattice model. The compounds Mg3Nd and Mg41Nd5 in the Mg–Nd–Zn system were treated as the formulae (Mg, Zn)3(Mg, Nd) and (Mg, Nd, Zn)41(Mg, Nd)5. The order–disorder transition between BCC_B2 and BCC_A2 phases was treated using a two-sublattice model (Mg, Nd, Zn)0.5(Mg, Nd, Zn)0.5. Based on experimental data, four stable ternary compounds τ1(Mg7Nd1Zn12), τ2(Mg7Nd2Zn11), τ3(Mg6Nd1Zn3) and τ4(Mg6Nd3Zn11) were taken into consideration in this system. A set of self-consistent thermodynamic parameters of the Mg–Nd–Zn system was obtained. Projection of the liquidus surface, selected vertical and isothermal sections were calculated using the proposed thermodynamic description. Comprehensive comparisons between the calculated and measured phase diagrams show that almost all the accurate experimental information is satisfactorily accounted for by the present thermodynamic description.

Based on the assessed three constituent binary systems and reported phase diagram data, the Co–Al–W ternary system was thermodynamically optimized by using CALculation PHAse Diagram (CALPHAD) method. The newly reported ternary phase γ′ was described with a two sublattice model, (Co,Al,W)0.75:(Co,Al,W)0.25, while liquid Fcc, Hcp(Co), and Bcc(W) were treated as substitutional solution phases. In order to describe the ternary solubility in the binary phases Co7W6 and CoAl, the models (Al,Co,W)7W2(Al,Co,W)4 and (Al,Co,W)0.5(Al,Co,W)0.5(Va)3 were, respectively, adopted. The rest 11 phases in the ternary systems were simply treated as stoichiometric compounds because their homogeneous ranges are small and can be neglected. A set of self-consistent parameters were obtained, which reasonably reproduced the phase relationship in Co-enriched corner. Finally, to confirm the reliability of the present assessment,the so-called Scheil–Gulliver model was used to simulate the solidification processes of three typical Co-based alloys. It was shown that the as-cast microstructures of the three ingots were well explained or predicted.

As an essential constitution of either Cu- or Zr-based bulk metallic glass alloys, the Al–Cu–Zr ternary system has aroused a great attention for decades. Since the three constituent binary systems, Al–Cu, Al–Zr and Cu–Zr, have been optimized previously, the focus of this work was only given to the Al–Cu–Zr ternary system. Based on the experimental enthalpies of mixing of ternary liquid and undercooled liquid alloys as well as the evaluated isothermal sections, the Al–Cu–Zr ternary system has been assessed using the CALPHAD method. Most of the calculated results show good agreement with the experimental thermodynamic data and the reported phase diagrams. By employing the driving force criterion with the present thermodynamic description, the observed glass-forming abilities in the Al–Cu–Zr system can be accounted for satisfactorily.

Mg-based alloys have been investigated widely due to the great potential for high performance structural applications. In the present work, the Mg–Sn binary system was re-optimized using the CALPHAD method through Thermo-calc ® software package on the basis of available experimental information. Combined with the previous assessments of the Mg–Zn and Sn–Zn binary systems, the thermodynamic modeling of the Mg–Sn–Zn ternary system was performed. The liquid phase is described by the associated solution model with an associate Mg 2 Sn, while the solid solution phases, hcp(Mg), bct(Sn) and hcp(Zn), are modeled by the substitutional solution model. The intermetallic compound Mg 2 Sn is treated as a stoichiometric compound and its Gibbs energy was assessed considering the experimental heat capacity and heat content. The solubility of Sn in the Mg–Zn intermetallic compounds, Mg 7 Zn 3 , MgZn, Mg 2 Zn 3 , MgZn 2 and Mg 2 Zn 11 , is not taken into account. Liquidus projection and many vertical sections of this ternary system were calculated. The calculated results are in good agreement with the reported experimental data.

The La–Zn and La–Mg–Zn systems are optimized by means of CALPHAD (CALculation of PHase Diagrams) approach based on available experimental data in terms of thermodynamic properties and phase equilibria. Parameters for the thermodynamic models of the La–Mg and Mg–Zn systems are adopted from the literature. Solution phases are all described with the substitutional solution model. To taken into account the order/disorder transition between the couple of phases Bcc_B2/Bcc_A2, a single Gibbs energy function is applied for both the ordered and the disordered state. Isoplethic and isothermal sections as well as the liquidus projection are calculated using the obtained thermodynamic descriptions. They show good agreement with reported experimental data.

Thermodynamic assessment of Ti-Co-Cu ternary system has been carried out by combining flrst-principle calculation and CALPHAD method. Firstly, formation enthalpies of stable and hypothesized compounds were calculated by flrst-principles method. Then, based on reported experimental information, a thermodynamic description of the Ti-Co-Cu ternary system was performed. Solution phases were treated as substitutional solutions of which excess Gibbs energies were formulated by Redlich-Kister polynomial, and the intermediate phases were described with sublattice models. All measured isothermal sections were reasonably reproduced. In addition, liquidus projection of this ternary system was further calculated, which may be useful for relevant materials processing.

Microstructure and phase equilibria of selected alloys of Hf–Si–B system have been studied in annealed conditions mainly by means of X-ray powder diffraction with aid of scanning electron microscope analysis. Compound Hf 5 Si 3 B 0.2 taking hexagonal structure (space group P 6 3 / mcm ), was confirmed with each unit cell containing two formulas and having lattice parameters a = 7.8557(1) A and c = 5.52622(1) A. Its crystal structure is made up of regular BHf 6 and HfSi 6 octahedra connected each other along direction by sharing common faces. This features a three-dimensional framework which is similar to that of analogue Mn 5 Si 3 structure. Besides, a thermodynamic description of Hf–Si–B system was developed based on its constituent binary systems and ternary experimental data from literatures and this work. Isothermal sections at 1273 K and 1573 K were calculated from our newly assessed thermodynamic description with comparison of experimental data.

Encouraged by the promising application of the Al–Cu–Sc system in the development of high strength aluminum alloy, the Al-rich region of this system was assessed by the CALPHAD approach. In order to make the models used for the phases in the three binary sub-systems compatible with each other, Al–Sc and Cu–Sc system were remodeled. Substitutional solution model was used for solution phases and sublattice model for binary intermetallic phases and the ternary compound Al8−xCu4+xSc. Comparisons between the calculated and experimental results showed that most of the experimental information was satisfactorily described by the present thermodynamic description.

Thermodynamic assessments of Ag–Dy and Ag–Er binary systems have been performed by using CALPHAD method. In order to provide necessary data for thermodynamic assessment, the formation enthalpies of Ag2Dy, AgDy, Ag2Er and AgEr were calculated by using projector augmented-wave (PAW) method within generalized gradient approximation (GGA) in first-principles frame. During assessments of the Ag–Dy and Ag–Er binary systems, the solution phases (liquid, fcc and hcp) were treated as substitutional solutions, of which the excess Gibbs energies were modeled by Redlich–Kister polynomial, and all intermetallic compounds were described as stoichiometric phases. Consequently, phase diagrams of these two binary systems were thermodynamically optimized and the self-consistent thermodynamic parameters of involved phases obtained.

Based on the critically assessed B–Si phase diagram, one alloy in the Si-rich side was selected and the temperature of the eutectic reaction L ↔ (Si) + SiB6 was measured to be 1636 K by means of DSC. Using a regular substitutional model for the liquid phase, the B–Si system was reassessed and extrapolated to higher-order systems. Thermodynamic description for the B–C–Si system was developed based on critically reviewed experimental data. The calculated phase diagrams were in good agreement with available experimental data.

The Ce–Cu binary system has been thermodynamically reassessed by CALPHAD approach based on experimental data and thermodynamic properties of phase diagram. Incorporating the thermodynamic evaluations of Al–Ce and Al–Cu systems from literature, the Al–Ce–Cu ternary system has been assessed using CALPHAD approach. The solution phases including liquid, Fcc and Bcc were treated as substitutional solution phases and the Redlich–Kister polynomial was used to describe their excess Gibbs energies. All binary and ternary intermetallic compounds were treated as stoichiometric phases and their Gibbs energies of formation were optimized. The calculated Al–Ce–Cu phase diagram agreed well with available experimental data.

The phase equilibria of the Sb–Y and Al–Sb–Y systems were analyzed and a complete thermodynamic description of this ternary system was obtained. The thermodynamic descriptions of the other two binary systems were taken from the literature. Most of the binary intermetallic phases, except Sb 3 Y 5 , were assumed to have no ternary solubility. Based on the experimental data, the calculated phase equilibria were in good agreement with the experimental data.

Based on the available experimental data of phase equilibria and thermodynamic properties from the literatures, the Co–Ho binary system has been thermodynamically assessed using the CALPHAD method. The solution phases, Liquid, FCC_A1, BCC_A2 and HCP_A3, were modeled as substitutional solution phases, of which the excess Gibbs energies were formulated with Redlich–Kister polynomial. Meanwhile, all intermetallic compounds were described as stoichiometric compounds. Subsequently, a set of self-consistent thermodynamic parameters describing various phases in this binary system has been obtained. The calculated results can reproduce well the corresponding experimental data.

On the basis of available experimental data of phase diagram and thermodynamic properties, the Sm–Zn binary system has been optimized using the CALPHAD method. The solution phases, liquid, bcc, hcp and rhombohedral, were treated as by substitutional solutions models, while the intermediate compounds, SmZn, SmZn 2 , SmZn 3 , Sm 3 Zn 11 , Sm 13 Zn 58 , Sm 3 Zn 22 , Sm 2 Zn 17 and SmZn 11 , were described as stoichiometric phases. A set of self-consistent parameters capable of formulating the Gibbs energies of various phases in this binary system has obtained. Calculation based on these parameters can reproduce most of the experimental data on thermochemistry and phase diagram reported in the literatures very well are satisfactory reproduced.

The reaction between Zr and SiC at 1473 K in vacuum has been studied. A layer structure was observed after high-temperature reactions between Zr and SiC complex. ZrCx was formed next to the SiC. Thermodynamic description for the C–Si–Zr system was developed based on its constituent binaries and critically reviewed experimental data. The Si–Zr binary has been modified. The high-temperature Zr5Si3 phase and the ternary compound Zr5Si3Cx was described as one phase, using the model (Zr)5(Si)3(C, Va)1. The calculated results were in good agreement with available experimental data.

The Ag–Nd binary system has been assessed with CALPHAD approach based on experiment information of phase equilibria and thermodynamic properties. The excess Gibbs energies of the solution phases including liquid, BCC, FCC and DHCP were formulated with Redlich–Kister polynomial functions. The intermetallic compounds Ag 51 Nd 14 , α-Ag 2 Nd, β-Ag 2 Nd, and AgNd were treated as stoichiometric phases. Self-consistent thermodynamic parameters have been obtained and the calculated results agree well with most of experimental data.

The Cu–Dy binary system has been thermodynamically assessed with CALPHAD approach. The solution phases including liquid, Bcc, Fcc and Hcp were treated as substitutional solution phases, of which the excess Gibbs energies were formulated with Redlich–Kister polynomial functions. The binary intermetallic compounds were treated as stoichiometric phases. A set of self-consistent thermodynamic parameters for describing various phases in this system has been obtained, which can well reproduce the corresponding experimental data.

Both B–Zr and Si–Zr binary systems have been thermodynamically reassessed with CALPHAD approach. The liquid is treated as substitutional solution phase, of which the excess Gibbs energies are formulated with Redlich–Kister polynomial functions. hcp-Zr and bcc-Zr are treated by interstitial model. Terminal solution β-B is treated as the formula (B) 93 :(B,Zr) 12 using two-sublattice model with B on the first sublattice and B, Zr on the second one. The binary intermetallic compounds, ZrB, ZrB 2 , ZrB 12 , Si 2 Zr, α-SiZr, β-SiZr, α-Si 4 Zr 5 , β-Si 4 Zr 5 , Si 2 Zr 3 , Si 3 Zr 5 , SiZr 2 and SiZr 3 are treated as stoichiometric phases. Subsequently, based on available experimental data from open literatures, optimization is performed using Parrot modules of Thermo-calc software package. And a set of self-consistent thermodynamic parameters describing each phase which appeared in these two systems have been obtained, which can reasonably reproduce the corresponding experimental data.

Based on the experimental data of phase equilibria and thermodynamic properties, the phase diagram of the Ag–Gd binary system was thermodynamically assessed by CALPHAD method. The solution phases including liquid, fcc (Ag), hcp (Gd) and bcc (Gd) were treated by simple substitutional model, of which the excess Gibbs energies were formulated with the Redlich–Kister polynomial. And three intermetallic compounds, AgGd, Ag2Gd and Ag51Gd14, were described as stoichiometric compounds. Finally, a set of self-consistent thermodynamic parameters formulating all the phases in the Ag–Gd binary system was obtained, which can reasonably reproduce all the experimental and thermodynamic data.

The Ga–Sc and Ga–Tb binary systems have been assessed with CALPHAD method. Liquid is treated as substitutional solution phase, of which the excess Gibbs energies are modeled by Redlich–Kister polynomial function. The binary intermetallic compounds are treated as stoichiometric phases. Thermodynamic parameters of various phases have been optimized and the calculated results are in reasonable agreement with experimental data.

On the basis of available experimental data of phase diagram and thermodynamic properties, the Pr–Zn binary system has been optimized using the CALPHAD approach. The phases, including liquid and bcc_A2(βPr) were treated as substitutional solutions, while the intermetallic compounds, including PrZn, PrZn2, PrZn3, Pr3Zn11, Pr13Zn58, Pr3Zn22, Pr2Zn17 and PrZn11 were modeled as stoichiometric compounds. As the result of optimization, a set of self-consistent thermodynamic parameters has been obtained, which can be used to reproduce the reported experimental data.

Interfacial reactions between different compositional Sn–Ag alloys and Ni substrate at 493 K for different durations were investigated. Only one intermetallic compound (IMC), Ni3Sn4, was detected at the interface. This result was attributed to combining effects of driving force for the IMC formation and diffusion of Ni across the interface. Furthermore, it was found that the growth of Ni3Sn4 layer at the interface with annealing time obeys a parabolic rule, which implies a diffusion-controlled mechanism. In addition, the thickness of Ni3Sn4 layer decreases with increasing Ag content in the Sn–Ag alloys.

A thermodynamic description of the Al–Yb binary system was developed based on critically evaluated experimental data by using CALculation of PHAse Diagram (CALPHAD) approach. Liquid (γYb) and (βYb) were modeled as substitutional solution phases. Al 2 Yb and Al 3 Yb were treated as stoichiometric compounds. A set of self-consistent parameters for describing various phases in this system was obtained, with which most of the experimental data reported in the literatures were well reproduced.

The isothermal section of the Cu–Ti–Zr ternary system at 1023 K has been constructed by using diffusion triple together with electron probe microanalysis, which consists of 15 single-phase fields, 25 two-phase fields and 13 three-phase fields. A ternary phase, Cu 2 TiZr, is confirmed. Most of the Cu–Ti and Cu–Zr binary phases show large ternary solubility, in which Zr and Ti can substitute for each other to a certain degree. In addition, at 1023 K, the CuTi 2 and CuZr 2 phase can form a continuous solution phase in the Cu–Ti–Zr ternary system.

The isothermal section at 923 K in the Co–Cu–Ti system was experimentally studied by using the diffusion triple technique together with scanning electron microscopy (SEM) and electron probe microanalysis (EPMA). High solubility of Cu, up to 22.5 at.% (substituting Co) in CoTi was observed at this temperature; and the solubility of Co (substituting Cu) in CuTi is also large which is up to 14.0 at.%. For other binary compounds CoTi 2 , CuTi 2 , Cu 4 Ti 3 and Cu 3 Ti 2 , the ternary solubilities are remarkable too. No ternary compound has been detected. Nine three-phase equilibria were determined and three others in the Ti-enriched corner were estimated. Further investigations are essential to confirm the possible ternary phase reported and to determine the invariant reactions in the ternary system.

Mg–Nd–Y alloys ingots were cast and annealed at 753 K, and then analyzed with scanning electron microscopy (SEM), X-ray diffraction (XRD) and electron-probe microanalysis (EPMA) to determine phase equilibria in the Mg-rich part of the Mg–Nd–Y system. Existence of the ternary compound β with Mg5Gd-type structure was verified, which is in the equilibrium with hcp_A3 (Mg). Furthermore, thermodynamic description of the Mg–Nd–Y system was carried out on the basis of the present experimental results. The thermodynamic parameters of the boundary Mg–Nd and Nd–Y binary systems were directly cited from literatures, while most of the parameters for the Mg–Y binary system were taken from the latest literature with an exception of a minor revision for the bcc_B2 phase in this paper. The ordered bcc_B2 and disordered bcc_A2 phases were described with a sublattice model (Mg,Nd,Y)0.5(Mg,Nd,Y)0.5 and their Gibbs energies were expressed with same function. Most of the binary intermetallic phases, except for Mg3Nd, were assumed to have no ternary solubility. The Mg3Nd and ternary compound β were treated as semistoichiometric compounds with mutual substitution between Nd and Y. Reasonable agreement of the phase equilibria in the Mg–Nd–Y ternary system between thermodynamic extrapolation and experiments was achieved.

Two isothermal sections of the Co–Cu–Ti ternary system at 973 and 1123 K were experimentally determined using the diffusion triple technique together with scanning electron microscopy and electron probe microanalysis. The solubility of Cu (substituting Co) in CoTi increased from 22.8 at.% at 973 K to 28.1 at.% at 1123 K while that of Co (substituting Cu) in CuTi decreased from 11.1 to 8.8 at.% accordingly. In addition, the solubility limits of the third element in the binary compounds CoTi2, CuTi2, Cu4Ti3, and Cu3Ti2 were remarkable. Besides the solubility change, we found the Cu2Ti phase was stable at 1123 K but disappeared at 973 K. A ternary compound “m” with a composition range covering Co10Cu57Ti33 was detected at both isothermal sections. An invariant reaction Cu4Ti3 + CoTi ↔ CuTi + m at a temperature between 973 and 1023 K was deduced. Further investigations are necessary to confirm the reactions among Cu, Cu4Ti, Cu2Ti, Cu3Ti2, and “m” between 1023 and 1123 K.

The isothermal section of the Co–Cu–Ti system at 1023 K was experimentally determined by using diffusion triple technique together with scanning electron microscopy (SEM) and electron probe microanalysis (EPMA). Additional alloy samples annealed at 1023 K were analyzed to further confirm the results. Cu 2 Ti was formed in diffusion couple and several alloy samples at 1023 K. Solubility of Cu in CoTi is 25.8 at.% (substituting Co), and that of Co (substituting Cu) in CuTi is 9.5 at.%. Other binary compounds such as CoTi 2 , CuTi 2 , Cu 4 Ti 3 and Cu 3 Ti 2 also have remarkable solubilities in ternary. And a ternary compound designated as “m” with a composition range covering Co 10 Cu 57 Ti 33 has been detected. With these results the 1023 K isothermal section has been established.

The Ag–Yb binary system has been thermodynamically assessed with CALPHAD approach. The solution phases including liquid, bcc and fcc were treated as substitutional solution phases, of which the excess Gibbs energies were formulated with Redlich–Kister polynomial functions. The binary intermetallic compounds were treated as stoichiometric phases. A set of self-consistent thermodynamic parameters for describing various phases in this system has been obtained, which can well reproduce the corresponding experimental data.

A high-efficiency combinatorial approach has been applied to rapidly build the database of composition-dependent elastic modulus and hardness of the Ti-Ta and Ti-Zr-Ta systems. A diffusion multiple of the Ti-Zr-Ta system was manufactured, then annealed at 1173K for 1800h, and water quenched to room temperature. Extensive interdiffusion among Ti, Zr and Ta has taken place. Combining nanoindentation and electron probe micro-analysis (EPMA), the elastic modulus, hardness as well as composition across the diffusion multiple were determined. The composition/elastic modulus/hardness relationship of the Ti-Ta and Ti-Zr-Ta alloys has been obtained. It was found that the elastic modulus and hardness depend strongly on the Ta and Zr content. The result can be used to accelerate the discovery/development of bio-titanium alloys for different components in implant prosthesis.

A series of creep ageing tests under different temperatures and stresses have been designed to characterize the creep aging behavior of 2124 Al alloy,and the microstructure and properties of the samples in the interrupted tests have been observed.On the basis of the experimental results, combining the creep mechanism and age strengthening theory,a unified constitutive model has been developed for creep age forming of 2124 Al alloy.The constitutive relations,aging strengthening effect and the microstructure are closely correlated in the model,which could be suitable for different ageing temperatures and stress levels.Finally,the model has been used to predict the creep strain curves of added creep aging tests with different temperature,the computed results tally well with the experimental data.