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The complete isothermal sections of the Hf–Nb–Ni system at 950 and 1100 °C were constructed, in which the phase constituents and compositions of alloy samples were determined by scanning electron microscopy with energy dispersive X-ray spectroscopy, and X-ray diffraction. Nine three-phase regions at 950 °C and nine three-phase regions at 1100 °C were confirmed. Four three-phase regions at 950 °C and five three-phase regions at 1100 °C were proposed. The solid solubilities of third components in the binary compounds were determined. A new ternary compound τ with Hf2Rh structure was found.

The phase equilibria of the Mo–Si–V ternary system were experimentally determined, including the isothermal sections at 1200 and 1450 °C, as well as the liquidus surface projection. The microstructures, crystal structures and phase constitutions of the as-cast and the annealed alloys in whole composition range were investigated by means of scanning electron microscopy equipped with energy dispersive spectroscopy, electron probe microanalyzer and X-ray diffraction. Five three-phase regions and ten two-phase regions were confirmed and no ternary compounds were observed in isothermal sections at 1200 and 1450 °C. In addition, the solidification paths of different Mo–Si–V alloys were analyzed to verify the primarily solidified phases. The stoichiometric compounds Mo5Si3 and V5Si3 have the same structure-type (W5Si3), however, they have two different compositions in the Mo–Si–V ternary system. They form two-line compounds Mo-rich Mo(V)5Si3 and V-rich V(Mo)5Si3. Eight primary solidification regions were finally confirmed on the basis of the study on the solidification processes of the as-cast alloys. The present experimental results are useful for the thermodynamic assessment of the Mo–Si–V ternary system, and the database development for the multi-component Nb/Mo–Si-based superalloy system.

The phase relationships at 950 °C and 1100 °C in the whole composition range of the Ni–Hf–Ta system were critically investigated using equilibrated alloys by scanning electron microscopy with energy dispersive spectrometry, and X-ray diffraction techniques. A ternary phase τ with Hf2Rh-structure was found in the annealed alloys, and the composition ranges of Ta were measured to be ~ 8.2 to 20.1 at. pct at 950 °C and ~ 7.1 to 20.7 at. pct at 1100 °C. The solid solubilities of Ta in the Ni–Hf binary compounds and Hf in the Ni–Ta binary compounds were determined. Two entire isothermal sections at 950 °C and 1100 °C in the Ni–Hf–Ta system were constructed, and 15 and 16 three-phase regions were determined, respectively.

Machine learning technologies have been extensively applied in high-performance information-processing fields. However, the computation rate of existing hardware is severely circumscribed by conventional Von Neumann architecture. Photonic approaches have demonstrated extraordinary potential for executing deep learning processes that involve complex calculations. In this work, an on-chip diffractive optical neural network (DONN) based on a silicon-on-insulator platform is proposed to perform machine learning tasks with high integration and low power consumption characteristics. To validate the proposed DONN, we fabricated 1-hidden-layer and 3-hidden-layer on-chip DONNs with footprints of 0.15 mm2 and 0.3 mm2 and experimentally verified their performance on the classification task of the Iris plants dataset, yielding accuracies of 86.7% and 90%, respectively. Furthermore, a 3-hidden-layer on-chip DONN is fabricated to classify the Modified National Institute of Standards and Technology handwritten digit images. The proposed passive on-chip DONN provides a potential solution for accelerating future artificial intelligence hardware with enhanced performance.

Phase equilibria involving the long-period stacking ordered phases including 14H, 18R and 10H in the Mg-rich corner of the Mg-Y-Zn system at 400 and 500°C have been experimentally investigated by using X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and high-angle annular dark-field scanning transmission electron microscopy (HAADF-STEM). The coexistence of 14H and 18R as well as 18R and 10H was confirmed from atomic scales. The phases 14H, 18R and 10H were all stable phases from 400 to 500°C.The experimentally proved three-phase equilibrium of 14H, 18R and α-Mg instead of 14H, 18R and Mg24Y5 were presented in the modified isothermal sections. The latter three-phase equilibrium was reported in the available literature. The modified isothermal sections are conducive to guide the composition design to obtain the alloys with favorable microstructure constituents and mechanical properties.

The diffusion triples of the Hf-Mo-Ni system were successfully fabricated by spark plasma sintering (SPS). The phase stability of intermetallics and phase equilibria relations of the Hf-Mo-Ni system were studied by diffusion triples and equilibrated alloys. A new intermetallic compound τ with Hf2Rh structure was detected, the composition of which is close to Hf:(Ni + Mo) = 2:1. NiHf3 with BRe3 structure was proven to be stable at 1100 °C and 950 °C in the Hf-Ni and Hf-Mo-Ni systems. The Mo solubility in the Ni7Hf2 phase was 4.9 at. pct at 1100 °C and 4.6 at. pct at 950 °C. The solubility of Mo in other compounds in the Hf-Ni system could be neglected. The solubility of Ni in αMo2Hf was 5.4 at. pct at 1100 °C and 3.8 at. pct at 950 °C. An invariant reaction αNiHf + bcc(Mo) ↔ Ni11Hf9 + αMo2Hf should occur between 950 °C and 1100 °C according to phase relations among αNiHf, bcc(Mo), Ni11Hf9, and αMo2Hf at 950 °C and 1100 °C.

Equilibrated alloys were characterized using SEM/EDX and XRD methods to identify the Co-Nb-Ni phase equilibria at 1100 °C and 900 °C. The isothermal section at 1100 °C was re-constructed and the partial phase relationships at 900 °C were further validated. The crystal structure of the ternary compound τ was proved to be of the Mg3Cd type with Pearson symbol hP8 and space group P63/mmc. The addition of nickel can increase the phase stability of Co7Nb2. The Co-Nb, Ni-Nb, and Co-Nb-Ni systems were assessed using the CALPHAD (CALculation of PHAse Diagram) method. The present experimental and calculated results can be used as a reference for developing and designing Co/Ni-based intermetallics and superalloys.

The liquidus surface projection and isothermal sections at 1200 and 1000 °C of the Fe-Ni-Ta system were established by Scanning Electron Microscopy (SEM) coupled with Energy Dispersive Spectrometry (EDS) and x-ray diffraction (XRD). Eight primary solidification regions in the liquidus surface projection were experimentally obtained. The similar phase relations were derived in the isothermal sections at 1200 and 1000 °C. Based on the experimental results in the present work and reported in the literature, the Fe-Ni-Ta system was optimized by means of CALPHAD (CALculation of PHAse Diagram) method. Solution phases (liquid, fcc, bcc) were treated as the substitutional solution. The compounds Fe2Ta, Ni2Ta, Ni3Ta and NiTa2 were treated as (Fe,Ni,Ta)m(Fe,Ni,Ta)n by a two-sublattice model, and (Fe,Ni)7Ta6 was modelled as (Fe,Ni,Ta)1(Ta)4(Fe,Ni,Ta)2(Fe,Ni,Ta)6 by a four-sublattice model. A set of self-consistent thermodynamic parameters for the Fe-Ni-Ta system was acquired.

SiC/7075 aluminum matrix composites were prepared by a liquid stirring method. The role of Ti facilitating the preparation of SiC/7075 aluminum matrix were studied by means of direct-reading spectrometer, scanning electron microscope, energy dispersive spectrometer, X-ray diffraction and the sessile drop method. The results show that the SiC content in the SiC/7075 composite increases with an increase of Ti addition. The addition of Ti can significantly improve the wettability of SiC/Al system, there is a critical value of above 0.5% of Ti content in improving the wettability of the Al/SiC system at 1 173 K. The temperature of the “non wetting-wetting” transition for the (Al-2Ti)/SiC system is about 1 123 K, the contact angle decreases to 88 ° at 200 seconds and reaches a stable contact angle of 28 ° at 2 100 seconds.

The liquidus projection and the isothermal section at 1 300 °C of the Nb–Si–V ternary system were experimentally studied. Using scanning electron microscopy, electron probe microanalysis and X-ray diffraction, the primary solidification phases and the precipitation paths in each region of the liquidus projection as well as the equilibrium relations of the phases in the isothermal section were determined. Ten primary solidification regions were found in the liquidus projection and eight three-phase equilibrium regions were observed in the isothermal section at 1 300 °C. The compounds βNb5Si3 with V5Si3 and NbSi2 with VSi2 are the phases of the same structure but different compositions and form two linear compounds βNb(V)5Si3 or V(Nb)5Si3 and Nb(V)Si2 or V(Nb)Si2, respectively The ternary linear compound (Nb,V)2Si with the stoichiometry about 2 : 1 of (Nb + V) : Si was found in both the liquidus projection and the isothermal section at 1 300 °C.

Two kinds of experimental methods were tried in the present work: (i) the powder metallurgy method combined with differential thermal analysis (DTA) to determine the metastable liquidus miscibility gap for a Fe–Cu binary system and (ii) the high-temperature melting method combined with isothermal treatment to determine the stable liquidus miscibility gap for a Fe–Sn binary system. The experimental method was adopted according to the characteristics of the liquidus miscibility gap of the specific system. Using the powder metallurgy method, a uniform microstructure morphology and chemical composition was obtained in the DTA specimen, and the phase-separation temperature of the supercooled metastable liquid was measured. The isothermal treatment was applied for the samples inside the stable liquidus miscibility gap; here, equilibrated compositions were reached, and a layered morphology was formed after rapid cooling. The liquid miscibility gaps of the Fe–Cu and Fe–Sn binary systems were measured, and the peak temperatures of the corresponding miscibility gaps were determined to be about 1417°C at x(Cu) = 0.465at% and 1350°C at x(Sn) = 0.487at%, respectively. On the basis of the experimental results, both the Fe–Cu and the Fe–Sn binary systems were thermodynamically assessed.

An integrated physical diffractive optical neural network (DONN) is proposed based on a standard silicon-on-insulator (SOI) substrate. This DONN has compact structure and can realize the function of machine learning with whole-passive fully-optical manners. The DONN structure is designed by the spatial domain electromagnetic propagation model, and the approximate process of the neuron value mapping is optimized well to guarantee the consistence between the pre-trained neuron value and the SOI integration implementation. This model can better ensure the manufacturability and the scale of the on-chip neural network, which can be used to guide the design and manufacturing of the real chip. The performance of our DONN is numerically demonstrated on the prototypical machine learning task of prediction of coronary heart disease from the UCI Heart Disease Dataset, and accuracy comparable to the state-of-the-art is achieved.

Magnetic transitional behaviors and magnetocaloric effect of the intermetallic compound Ho3Pd2 have been studied. It exhibits a second order magnetic transition from ferromagnetic (FM) to paramagnetic (PM) states at a Curie temperature (TC) of 9.6 K. In the PM region, the magnetic susceptibility of the Ho3Pd2 compound follows the Curie-Weiss law. The paramagnetic Curie temperature (θp) was evaluated to be 5.3 K, and the effective magnetic moment (μeff) to be 10.5 μB/Ho. The positive value of θp indicates the ferromagnetic interactions in the ordering state of Ho3Pd2 and the effective magnetic moment is close to the theoretical value 10.6 μB for the Ho3+ ion, which suggests that the Pd ions in Ho3Pd2 are non-magnetic. Under the magnetic field change of 0–5 T, the maximum magnetic entropy change (−ΔSM) and the refrigerant capacity (RC) for this compound are evaluated to be 18.3 J kg−1 K−1 and 301.5 J kg−1, respectively, with no thermal and field hysteresis loss.

The phase equilibria at 1473, 1373 and 1273 K in the Fe–Ta–Ti system were investigated by means of Scanning Electron Microscopy (SEM) with Energy Dispersive Spectrometer (EDS) and X-ray Diffraction (XRD). The experimental results indicated that Fe2Ta and Fe2Ti formed the continuous solid solution phase Fe2(Ta,Ti). No ternary compound was found in this system. The temperature of invariant reaction liquid + Fe7Ta6 → FeTi + bcc(Ta,Ti) was measured as 1431 K by Differential Thermal Analysis (DTA). Based on the experimental results in the present work, the Fe–Ta–Ti system was optimized using CALPHAD technique. A set of self-consistent thermodynamic parameters for the Fe–Ta–Ti system was obtained, and the experimental isothermal sections at 1473, 1373 and 1273 K were reproduced well.

The liquidus surface projection of the Fe-Mo-Nb ternary system was constructed by means of X-ray diffraction, scanning electron microscopy coupled with energy dispersive X-ray spectroscopy, and differential thermal analysis. The experimental results indicate that the liquidus surface projection consists of six primary solidification regions and four ternary invariant reactions. On the basis of the experimental results in the present work and isothermal sections taken from the literature, the Fe-Mo-Nb system is modeled using the CALculation of PHAse Diagram (CALPHAD) method. Solution phases, liquid, bcc, and fcc, are treated as the substitutional solution. The μ and Fe2(Mo, Nb) phases are treated as (Fe, Mo, Nb)1(Mo, Nb)4(Fe, Mo, Nb)2(Fe, Mo, Nb)6 and (Fe, Mo, Nb)2(Fe, Mo, Nb)1 using the sublattice model, respectively. A set of self-consistent thermodynamic parameters is thus obtained. The experimental liquidus surface projection and isothermal sections at 900 °C, 1100 °C, and 1200 °C are reproduced using the present thermodynamic description.

The crystal structure of Co3Ta was identified to be of the BaPb3 type having hexagonal R 3 ¯ m symmetry and Pearson symbol hR36 on the basis of X-ray diffraction data. The solidification process of the as-cast Co Ni Ta alloys and phase equilibria at 1473 K of the annealed Co Ni Ta alloys were studied by using scanning electron microscopy (SEM) with energy dispersive X-ray spectroscopy (EDX), X-ray diffraction (XRD) and differential thermal analysis (DTA) techniques. The liquidus surface projection and isothermal section at 1473 K of the Co Ni Ta system were first established. The liquidus surface projection consisted of 11 primary solidification regions and 9 ternary invariant reactions, and the isothermal section at 1473 K was made up of 8 three-phase regions and 17 two-phase regions. The addition of nickel can stabilize Co3Ta such that the peritectic temperature is at least 1594 K in the Co Ni Ta system, which is higher than the peritectoid one at 1306 K in the Co Ta system. The present experimental results could be used as guidance to cobalt-based superalloys and offer potential candidates for cobalt/nickel intermetallic compounds.

By scanning electron microscopy equipped with energy dispersive spectrometer, x-ray diffraction and differential thermal analysis, the microstructures and the solidification paths of 99 as-cast Al-Co-Ti ternary alloys, the phase constituents and the compositions of 94 annealed alloys were investigated. The liquidus surface projection and the isothermal section at 800 °C of the Al-Co-Ti system were constructed over the entire composition range. Three ternary intermetallic compounds Al2CoTi, AlCo2Ti and Al67Co4Ti29 were confirmed in the as-cast and annealed alloys. In the liquidus surface projection, 20 primary phase regions were included. In the isothermal section at 800 °C, there were 21 stable single-phase regions, 42 two-phase regions and 22 three-phase regions. The compositions of the ternary intermetallic compounds at 800 °C were determined as 21.25-26.79 at.% Co and 26.82-56.04 at.% Al for Al2CoTi, 47.65-54.85 at.% Co and 15.13-34.49 at.% Al for AlCo2Ti, and 6.04 at.% Co and 66.51 at.% Al for Al67Co4Ti29.

The liquidus surface projection and isothermal section at 1273 K of the Ni–Ti–V system were established using X-ray diffraction (XRD), scanning electron microscopy (SEM) coupled with energy dispersion spectroscopy (EDS), electron probe micro-analyzer (EPMA) and differential thermal analysis (DTA) techniques. Six primary solidification regions and four invariant reactions were deduced in the liquidus surface projection, and six three-phase regions were derived in the isothermal section at 1273 K. No ternary compound was observed. According to the experimental results in the present work and literatures, the Ni–Ti–V system was modeled by means of the CALPHAD (CALculation of PHAse Diagram) method. Two-sublattice model (Ni,Ti)10(Ni,Ti)20 for binary σ phase was used, and the thermodynamic parameters of the σ and NiV3 phases in the Ni–V system was reassessed. Solution phases (liquid, fcc, bcc and hcp) were modeled with the substitutional solution model in the Ni–Ti–V system. The compounds, Ni3Ti, NiTi2, Ni3V and σ, were treated as (Ni,Ti,V)m(Ni,Ti,V)n, and B2 were treated as (Ni,Ti,V)0.5(Ni,Ti,V) 0.5Va3. A set of self-consistent thermodynamic parameters of individual phases was obtained.

The isothermal section at 1273 K of the Co–Ni–Ti system was determined using equilibrated alloys by means of scanning electron microscopy (SEM) with energy dispersive X-ray spectroscopy (EDX) and X-ray diffraction (XRD). The experimental results indicated that eight three-phase regions and a ternary compound τ with Co3V-structure existed. Meanwhile, this system was thermodynamically modeled using the CALculation of PHAse Diagram (CALPHAD) method. The isothermal section at 1273 K measured in this work as well as the four isothermal sections at 1373, 1273, 1223 and 1173 K and the liquidus surface projection from the literatures were taken into account in the present optimization work. A set of self-consistent thermodynamic parameters of the Co–Ni–Ti system was first derived.

On the basis of all the presently determined experimental data, as well as the formerly reported isothermal sections of the Ce-Co-Sb ternary system, it was thermodynamically assessed by means of CALPHAD technique. For Ce-Co and Co-Sb binary systems, thermodynamic parameters previously obtained were considered and a re-assessment work of the Ce-Sb system is presented. In particular, the Kaptay exponential model, rather than the Redlich-Kister polynomials, is used to describe the interactions between Ce and Sb in the liquid phase of the Ce-Sb system, mainly to avoid the abnormal miscibility gap of liquid phase in the Ce-Co-Sb system at the Co rich region, and also to guarantee the consistent phase equilibria between the experimental isothermal sections and the calculated ones of the Ce-Co-Sb ternary system. The ternary compound CeCouSb2 is modeled as Ce2/9(Co%,Va)1/3Sb4/9 in order to describe the fluctuation of Co atoms in this compound. The ternary compound CeCoSb3 is regarded as a stoichiometric phase. The previously optimized thermodynamic parameters of other phases were adopted in the present work. A set of self-consistent thermodynamic parameters were finally obtained and fit well with the experimental results from various literatures, which will contribute to the further development of the CoSb3-based thermoelectric materials, especially from the perspective of the couping of electron-phonon interactions.

With consideration of the phase equilibrium dependency upon temperature (T) and pressure (P), the P-T type phase diagrams of Mg and Zr unary systems are constructed. The gaseous phase of the Mg system consists of the species Mg (g) and Mg2 (g), and the condensed phases are liquid, hexagonal close-packed (HCP_A3) and body centered cubic (BCC_A2). Similarly, the gaseous phase of the Zr system consists of the species Zr (g) and Zr2 (g), and the condensed phases are liquid, HCP_A3 (α), BCC_A2 (β) and a more open hexagonal structure (ω). The ω phase has a hexagonal lattice with three atoms per unit cell at (0, 0, 0), (1/3, 2/3, c/2a) and (2/3, 1/3, c/2a), where the c/a ratio is ∼0.62. The real solution model is applied to describe the molar Gibbs free energy of gaseous species by taking the fugacity coefficient into account to ensure the validity of the calculated phase diagrams under high temperature and high pressure. As for the description of the molar Gibbs free energy for condensed phases, the temperature and pressure dependent Murnaghan equation is employed, which is represented by Gpress and is correlated with the molar volume, the variations of voluminal thermal expansivity and compressibility with temperature, and the variation of bulk modulus with pressure. Based on the literature data available, the parameters of the pressure contribution part Gpress for the condensed phases are optimized by use of Pandat Software package. The calculated phase diagrams are well comparable with the experimental and theoretical reports. The favorable consistency between the calculated results for the optimized mechanical and thermophysical properties, such as the variations of the molar volume and the volume ratio with pressure and the molar heat capacity with temperature, and the experimental measurements from literatures further proves the reliability of the present thermodynamic assessment. According to the calculated results, it is indispensable for the contribution of Gpress to the global molar Gibbs free energy to be taken into consideration as the magnitude of pressure exceeds the order of 109 Pa. This CALPHAD method for developing the phase diagrams of Mg/Zr unary systems at high temperature and high pressure can be extended to study other unary systems.

The phase equilibria of the Nb-V binary system in the low temperature range below 850 °C have been investigated in order to determine the miscibility gap of its solid solution. By means of the approaches of the isothermal treatment of the alloys and diffusion couples as well as the differential thermal analysis (DTA), it has been proved that there is an immiscible region at low temperature, and the solid solution β (BCC_A2) separated into two phases with the same crystal structure but the different compositions, the Nb-rich βNb and the V-rich βV phases. The microstructures formed after both the spinodal decomposition and the nucleation decomposition have been observed by transmission electron microscopy (TEM). On the basis of the present experimental data as well as the related literature reports, the thermodynamic parameters of the Nb-V binary system were optimized and a 6 set of self consistent thermodynamic data was obtained. By use of the optimized thermodynamic data, the miscibility gap of the Nb-V solid solution and its spinodal decomposition range were calculated and presented.

The isothermal sections of the Fe-Mo-Nb system at 1100 °C and 1200 °C were constructed using X-ray diffraction and scanning electron microscopy coupled with energy dispersive spectroscopy. The experimental results indicate that the isothermal section at 1100 °C consists of six single-phase, nine two-phase, and four three-phase regions. At 1200 °C, there are six single-phase, eight two-phase, and three three-phase regions. The maximum solubilities of Mo in C14-Fe2Nb and μ-Fe7Nb6, and Nb in μ-Fe7Mo6 were determined to be about 26.97, 7.35, 19.74 at. pct at 1100 °C, respectively. The corresponding maximum solubilities of Mo at 1200 °C were determined to be about 25.08, 10.40, 23.85 at. pct at 1200 °C, respectively. No ternary compounds were observed at 1100 °C and 1200 °C.

Spark plasma sintering (SPS) was used to fabricate the Co−Hf−Mo−Ni diffusion multiple in a designed geometry to contain two Co−Hf−Mo and Co−Hf−Ni diffusion triples in one sample, which offers a high-efficiency and low-cost method for preparing this diffusion multiple. In this work, the phase equilibria of the Co−Hf−Mo system at 1373 and 1223 K were established according to the analysis of results obtained using a scanning electron microscope (SEM), X-ray diffraction (XRD), and electron probe microanalysis (EPMA) from annealed diffusion triples and equilibrated alloys. The homogeneity range of the ternary compound τ with Hf9Mo4Co structure was verified in diffusion triples, and solubilities of Mo in Co−Hf, Co in Mo−Hf, and Hf in Co−Mo binary compounds were detected at 1373 and 1223 K. The isothermal sections over the entire composition range at 1373 and 1223 K were successfully constructed. The obtained phase equilibria data provide guidance for the development of multicomponent γ/γ′ Co-based superalloys

By means of the CALPHAD (CAlcultion of PHAse Diagram) technique, the Hf–Pt system was critically assessed. Based on the experimental data, the four solution phases (liquid, fcc, bcc and hcp) were described with the substitutional solution model. The intermetallic compounds Hf3Pt4 and αHfPt were treated as the formula (Hf,Pt) m (Hf,Pt) n by a two-sublattice model. Based on the solid solution range, the intermetallic compounds HfPt4 and Hf2Pt were treated as the formula (Hf,Pt)1(Pt)3 and (Hf)2(Hf,Pt)1, respectively. The intermetallic compound Hf2Pt3 was treated as a stoichiometric compound. The formulas (Hf,Pt)0.5(Hf,Pt)0.5 · (Va)3 and (Hf,Pt)0.25(Hf,Pt)0.75(Va)0.5 were applied to describe the compounds βHfPt with CsCl-type structure (B2) and HfPt3 with Ni3Ti-type structure (D024) to cope with the order-disorder transition from bcc-A2 to bcc-B2 and hcp-A3 to hcp-D024. A set of self-consistent thermodynamic parameters of the Hf–Pt system was obtained.

The Ni–Ta system was experimentally determined and thermodynamically optimized in the present work. In experimental work, 12 as-cast and 12 annealed alloys were measured using scanning electron microscopy (SEM) with energy dispersive X-ray spectroscopy (EDX) and powder X-ray diffraction (XRD) techniques, and 5 crucial annealed alloys were determined using differential scanning calorimetry (DSC) method. It was found that Ni8Ta did not exist in both as-cast and annealed samples, and then two invariant reactions liq. → fcc(Ni) + Ni3Ta and liq. → Ni2Ta + μ-NiTa were modified. In the thermodynamic optimization, the solution phases liquid, fcc(Ni) and bcc(Ta) were treated with a substitutional solution model, three compounds Ni3Ta, Ni2Ta and NiTa2 were described using a two-sublattice model, and the compound μ-NiTa was modeled as (Ni,Ta)1Ta4(Ni,Ta)2(Ni,Ta)6 using a four-sublattice model. A set of self-consistent thermodynamic parameters of the Ni–Ta system was obtained.

The phase equilibria in the Fe-Nb-Ta ternary system at 1200, 1100 and 1000 °C were experimentally investigated. The microstructure of each sample was observed using scanning electron microscopy, and phase compositions were measured by energy dispersive spectrometry. The constituent phases of typical samples were analyzed with x-ray diffraction. The experimental results indicated that the continuous solid solution phases, Fe2(Nb,Ta) and Fe7(Nb,Ta)6, were formed between Fe2Nb and Fe2Ta and Fe7Nb6 and Fe7Ta6, respectively, and no ternary compounds were found in this system in these isothermal sections. Based on the experimental phase equilibria data obtained in the present work, three isothermal sections at 1200, 1100 and 1000 °C were constructed.

The liquidus surface projection and isothermal section at 1373 K of the Co–Ni–Ti system have been established by using the methods of scanning electron microscopy (SEM) with energy dispersive X-ray spectroscopy (EDX), powder X-ray diffraction (PXRD), and differential thermal analysis (DTA). 9 primary solidification regions and 6 ternary invariant reactions were deduced in the liquidus surface projection. 7 three-phase regions and 16 two-phase regions were derived in the isothermal section at 1373 K. Besides, the PXRD results indicated that the ternary compound τ with Co3V-structure existed in both liquidus surface projection and isothermal section at 1373 K. The ternary compound τ formed the extended primary field in the centre of the liquidus surface projection and its homogeneity ranges of Co in the isothermal section were measured to be from 34 to 51 at%. The present experimental results could be used as guidance to practical applications and input to future thermodynamic assessments.

Rhenium was one of important alloying elements in the Ni-based superalloys. Based on the molar Gibbs energy of the pure Re updated in SGTE Pure 5 database, the Re–X(X=Al, Co, Cr, Ta) systems were re-optimized by means of CALPHAD (CALculation of PHAse Diagrams) technique. In the present work, the phases liquid, fcc, bcc and hcp were described using a substitutional solution model. The phases AlRe, Al3Re, Al6Re, Al12Re, AlRe2 and Al11Re4 in the Re–Al system were described as stochiometric compound. The Al4Re_H and Al4Re_L instead of Al4Re were evaluated in the present work. The phases σ in the Re–Cr and Re–Ta systems and χ in the Re–Ta system were modeled as (X, Re)10(X, Re)20 (X=Cr or Ta) and Re24(Re, Ta)10(Re, Ta)24, respectively. A set of self-consistent thermodynamic parameters of the Re–X systems were obtained and the optimized results were in good agreement with the experimental data.

The Ce-Co-Sb ternary system is experimentally investigated, including the isothermal section at 823 K and the supplementary measurements at 673 K, as well as the liquidus projection of this system. For the isothermal section at 823 K, the phase equilibria in the whole composition range are determined using the equilibrated alloys prepared by the combination of arc melting method and high frequency melting method under the protection of an argon atmosphere, in case of the volatility of Sb and the oxidation of Ce. To confirm the phase relations at 673 K from previous literature report, some phase equilibria are re-determined on the basis of supplementary experiments. Two ternary compounds, (CeCouSb2) and CeCoSb3 are observed and the isothermal sections of the Ce-Co-Sb system at 823 and 673 K are finally constructed. The solidification paths of the Ce-Co-Sb as-cast alloys are analyzed to ascertain the primarily solidified phases from liquid. Both the liquidus projection and the isothermal sections of the Ce-Co-Sb system are determined based on the microstructures, crystal structures and phase compositions determined by scanning electron microscopy, X-ray diffraction and electron probe micro-analyzer, respectively. Some phase transition temperatures of the Ce-Co rich region are determined by means of differential scanning calorimeter.

These data and analyses support the research article "Experimental study on phase relations in the Ce-Fe-Sb ternary system" Zhu et al. (2017) [1]. The data and analyses presented here include the experimental results of XRD, SEM and EPMA for the determination of the whole liquidus projection and the isothermal section at 823 K in the Ce-Fe-Sb system. All the results enable the understanding of the constituent phases and the solidification processes of the as-cast alloys as well as the phase relations and the equilibrium regions at 823 K in the Ce-Fe-Sb ternary system over the entire composition. ispartof: DATA IN BRIEF vol:16 pages:211-226 ispartof: location:Netherlands status: published

The isothermal sections at 1373 and 1473 K in the Co–Nb–Ti system were constructed using annealed diffusion couples and equilibrated alloys by using scanning electron microscopy with energy dispersive spectroscopy (SEM/EDS), electron probe microanalysis (EPMA), and X-ray diffraction (XRD) techniques. Three three-phase regions, Co2(Nb,Ti) + Co7Nb6 + CoTi, Co7Nb6 + CoTi + bcc(Nb,Ti), and CoTi + liquid + bcc(Nb,Ti) were determined. Co3Nb and α-Co2Ti with a C36 crystal structure, and Co2Nb and β-Co2Ti with a C15 crystal structure at 1373 and 1473 K formed continuous solid solutions Co3(Nb,Ti) and Co2(Nb,Ti), respectively. The solubilities of Ti in Co7Nb6 and Nb in CoTi are determined to be ~11.4 at% and ~22.3 at% at 1373 K, and ~12.5 at% and ~24.8 at% at 1473 K, respectively. No ternary compounds were observed.

The alloy composition and the heat-treatment temperature of a Mg86Y8Zn6 (at%) alloy with sole long-period stacking ordered (LPSO) structures 18 R and 14 H was tailored under the assistance of thermodynamic Mg-Y-Zn phase diagram calculations. Before the tailoring for the Mg86Y8Zn6 alloy, a real alloy Mg86.2Y7.7Zn6.1 was studied for comparison between the thermodynamic calculations and the experimental measurements, indicating the effectiveness of the phase equilibrium design approach. Scanning electron microscopy (SEM) with energy dispersive spectrometry (EDS), transmission electron microscopy (TEM) and high-angle annular dark-field scanning transmission electron microscopy (HAADF-STEM) was used for microstructure and phase analyses. After annealing at 500 °C for 240 h, the microstructure of the as-cast Mg86.2Y7.7Zn6.1 alloy composed of α-Mg, W-Mg3Y2Zn3, 18 R and 14 H was thoroughly transformed to that solely composed of 18 R and 14 H. The validated design approach indicates a narrow composition and temperature window to avoid phases such as α-Mg or W-Mg3Y2Zn3.