Predicting single phase stability and segregation in the NbMoTaTi-(W,V) high entropy alloy system with the vacancy exchange potential

SCRIPTA MATERIALIA

卷:191

Article

McAlpine, Samuel W.¹  Logan, Julie, V¹  Short, Michael P.¹ 

[1] MIT, Dept Nucl Sci & Engn, 77 Massachusetts Ave, Cambridge, MA 02139 USA

关键词: High entropy alloys;    Refractory metals;    Ab initio calculation;    Vacancies;    Casting;   

DOI  :  10.1016/j.scriptamat.2020.08.043

来源: Elsevier

【 摘 要 】

High entropy alloys (HEAs) are potential next-generation structural materials, yet accurate prediction of phase stability remains a challenge. We study two equimolar refractory high entropy alloys, NbMoTaTi-X (X = W, V). Ab initio calculations are performed to determine the vacancy exchange potential in both alloys. Results and experimental confirmation indicate that a zero/low vacancy exchange potential predicts phase instability in NbMoTaTiW, while elemental trends of the same predict segregation in single phase NbMoTaTiV. If these results hold true across other systems, vacancy exchange potential can serve as a rapid predictor of stability in the vast HEA compositional space. (C) 2020 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

【 授权许可】

Free