NbTaV-(Ti,W) refractory high-entropy alloys: Experiments and modeling

• Published in: Materials science & engineering. A, Structural materials : properties, microstructure and processing Vol. 674; no. C; pp. 203 - 211
• Main Authors: Yao, H.W., Qiao, J.W., Gao, M.C., Hawk, J.A., Ma, S.G., Zhou, H.F., Zhang, Y.
• Format: Journal Article
• Language: English
• Published: United States Elsevier B.V 30-09-2016; Elsevier
• Subjects: Alloys; Compressive strength; Computer simulation; Design; Ductile; High-entropy alloys; MATERIALS SCIENCE; Mathematical models; Modelling; Phase transformations; Refractories; Refractory; Single-phase; Yield strength; Refractory; Single-phase; Design; High-entropy alloys; Ductile
• ISSN: 0921-5093; 1873-4936
• DOI: 10.1016/j.msea.2016.07.102

This study reports the design and development of ductile and strong refractory single-phase high-entropy alloys (HEAs) for high temperature applications, based on NbTaV with addition of Ti and W. Assisted by CALPHAD modeling, a single body-centered cubic solid solution phase was experimentally confirmed in the as-cast ingots using X-ray diffraction and scanning electron microscopy. The observed elemental segregation in each alloy qualitatively agrees with CALPHAD prediction. The Vickers microhardnesses (and yield strengths) of the alloys are about 3 (and 3.5–4.4) times that those estimated from the rule of mixture. While NbTaTiVW shows an impressive yield strength of 1420MPa with fracture strain of 20%, NbTaTiV exhibits exceptional compressive ductility at room temperature.