Thermodynamic assessment of the Mo–Nb–Ta system

Xiong, Wei; Du, Yong; Liu, Yong; Huang, Baiyun; Xu, Honghui; Chen, H.L.; Pan, Zhu

doi:10.1016/j.calphad.2004.07.002

Cited by 64 publications

(5 citation statements)

References 14 publications

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“…Coefficient, L m ij , is the interaction parameter of liquid solution phase, and their values are obtained from the Co‐Hf 32 , Co‐Nb 37 , Co‐Ta 34 , Hf‐Nb 38 , Hf‐Ta 39 , and Nb‐Ta 40 binary phase systems. Note that the ternary and quaternary interaction parameters are neglected in this study.…”

Section: Resultsmentioning

confidence: 99%

Low‐temperature synthesis and oxidation resistance of random combination of Hf, Nb, and Ta carbides microcuboids

Geng

Huang

et al. 2022

J Am Ceram Soc.

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Based on the dissolution‐precipitation mechanism, this article successfully synthesized binary and ternary transition metal carbide microcuboids with random combinations of Hf, Nb, and Ta by annealing monocarbides/cobalt powders. Accelerated mass transport rate through the flow of molten alloys (Co‐Hf‐Nb‐Ta) instead of slow solid diffusion made the low‐temperature pressureless sintering technique (1500°C) a reality. Furthermore, the equilibrium morphology was driven by the gradient Gibbs potential of carbides induced by the different local curvature of powders and anisotropic interfacial energy. (Hf0.5Ta0.5)C possessed the optimal oxidation resistance among all mentioned carbides, even competed with (Hf1/3Nb1/3Ta1/3)C. During the isothermal oxidation at 800∼1200°C, the doping of Nb and Ta in carbides assisted the monoclinic‐orthorhombic HfO2 transition at ambient pressure, besides, TaC can also restrain the orthorhombic‐monoclinic transition of Nb2O5. Moreover, oxidation kinetics parameters concluded that the addition of HfC and TaC contributed to the decreasing reaction order and the increasing activation energy, respectively.

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Section: Resultsmentioning

confidence: 99%

Low‐temperature synthesis and oxidation resistance of random combination of Hf, Nb, and Ta carbides microcuboids

Geng

Huang

et al. 2022

J Am Ceram Soc.

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“…where L is the interaction parameter. Based on the interaction parameters of the binary Ni-Cu [34], Ni-Nb [35], Ni-Ta [36], Cu-Nb [37], Cu-Ta [38], Nb-Ta [39], in this work a thermodynamic assessment is roughly performed for the liquid Ni-Cu-Nb-Ta alloy system because of the lack of the thermodynamic parameters of the corresponding ternary and quaternary systems. Figure 6 shows the pseudo-binary section of the miscibility gap of the (Ni 0.625 Nb 0.3125 Ta 0.0625 ) 100-x Cu x alloy.…”

Section: Resultsmentioning

confidence: 99%

Ni-Based Metallic Glass Composites Containing Cu-Rich Crystalline Nanospheres

Sun

et al. 2018

Acta Metall. Sin. (Engl. Lett.)

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In this work, a quaternary Ni-Cu-Nb-Ta system has been designed to obtain composite microstructure with spherical crystalline Cu-rich particles embedded in amorphous Ni-rich matrix. The alloy samples were prepared by using singleroller melting-spinning method. The microstructure and thermal properties of the as-quenched alloy samples were characterized by X-ray diffraction, scanning electron microscopy, high-resolution transmission electron microscopy, and differential scanning calorimetry. It shows that the spherical crystalline Cu-rich particles are embedded in the amorphous Ni-rich matrix. The average size of the Cu-rich particles is strongly dependent upon the Cu content. The effect of the alloy composition on the behavior of liquid-liquid phase separation and microstructure evolution was discussed. The phase formation in the Ni-based metallic glass matrix composite was analyzed.

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“…The microstructure of the Al−Nb−Ta−Ti alloys and thermal effects determined with DTA have been explained through thermodynamic modeling with the CALPHAD method (Thermo-Calc software, version S). The thermodynamic description of the quaternary system combined: (i) the models and parameters of constituent binary Nb−Ta [82], Nb−Ti [83], Ta−Ti [84] systems and (ii) the models and parameters of the constituent ternaries Al−Nb−Ti [10] (corrected as in Table 3), Al−Ta−Ti [11], and Al−Nb−Ta. It should be noted that the thermodynamic modeling and optimization of the thermodynamic parameters of the last system took into account the results of experimental study of phase equilibria at 925°C [85,86].…”

Section: Resultsmentioning

confidence: 99%

Structure and properties of titanium-aluminum alloys doped with niobium and tantalum

Bondar

Witusiewicz

Hecht

et al. 2011

Powder Metall Met Ceram

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melted in a laboratory arc furnace from pure components (~99.9 wt.%) are studied by X-ray diffraction (XRD), scanning and transmission electron microscopy (SEM and TEM), differential thermal analysis (DTA), and compression testing. The alloys are found to consist mainly of a superfine lamellar structure of decomposition β → α → α + γ → α 2 + γ and contain tiny islands of the γ phase and also the β phase at 12 at.% Nb or Ta. The CALPHAD approach is used to obtain a thermodynamic description of the Al−Nb−Ta−Ti system, which adequately reproduces the experimental data. The compression tests performed at room temperature show that the ternary alloys with 45 at.% Al are characterized by higher strength but lower plasticity than the alloys with 47 at.% Al. For the Ti 46 Nb 8 Al 46 and Ti 46 Ta 8 Al 46 alloys, high strength in the temperature range 20−800°C and a drop in plasticity to 2−4% at 200−600°C are revealed. Among the quaternary alloys examined, the best combination of strength and plasticity (σ 02 = 1043 MPa, σ ult = 1612 MPa, ε pl = 12.4%) is exhibited by the Ti 47 Nb 4 Ta 4 Al 45 alloy.

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Thermodynamic assessment of the Mo–Nb–Ta system

Cited by 64 publications

References 14 publications

Low‐temperature synthesis and oxidation resistance of random combination of Hf, Nb, and Ta carbides microcuboids

Low‐temperature synthesis and oxidation resistance of random combination of Hf, Nb, and Ta carbides microcuboids

Ni-Based Metallic Glass Composites Containing Cu-Rich Crystalline Nanospheres

Structure and properties of titanium-aluminum alloys doped with niobium and tantalum

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