Atomic and vacancy ordering in carbide ζ-Ta4C3−x (0.28⩽x⩽0.40) and phase equilibria in the Ta–C system

Prediction of the material with highest known melting point fromab initiomolecular dynamics calculations

“…Our investigation focuses on the rocksalt structure in the Hf-Ta-C systems, because it is the only stable solidstate form in the temperature region of melting [26,27]. Employing the small-cell coexistence method [24], we calculate the melting temperatures of rocksalt HfC x (x ∈ [0.75, 1]), as shown in Fig.…”

Joining of ultra-refractory carbides

“…In the Ta-C and Nb-C systems, both monocarbides and carbides with compositions Ta 2 C, Ta 4 C 3 and Nb 2 C are stable, 26,43 leading to a broader range of microstructural possibilities. Both a mixed (Ta,Nb)C and an adjoining and separate layer containing Ta 2 C and Ta 4 C 3 were observed in the joint involving TaC.…”

Quantification of Oxide Inclusions and Porosity Structure in a Tantalum Carbide Microstructure Fabricated From Carbothermal Reduced Tantalum Oxide Precursor Powders

“…X‐ray diffraction (XRD) for phase identification and estimated volume fraction determination was done using a Bruker Discovery D8 General Area Diffraction Detector System (Bruker AXS, Madison, WI) with Cu K α radiation at 45 keV and 40 mA as the source. The TaC, Ta 2 C, and Ta 4 C 3 phases were identified using data from Wyckoff, Lissner and Schleid, and Gusev et al . sources, respectively.…”

“…sources, respectively. The phase content is tabulated in Table and was estimated by the integrated intensity of the theoretically most intense peak for each phase, normalized by the multiplicity of the planes, which are the {111} TaC , , and reflections, divided by the sum of all maximum peak intensities . The oxide phase, Ta 2 O 5 , which was not observed in the XRD diffractogram because of its small volume fraction was determined using electron diffraction, given below, and compared with data reported by Zibrov et al …”