Carbide Formation in Refractory Mo15Nb20Re15Ta30W20 Alloy under a Combined High-Pressure and High-Temperature Condition

Congyan Zhang; Uttam Bhandari; Congyuan Zeng; Huan Ding; Shengmin Guo; Jinyuan Yan; Shizhong Yang

doi:10.3390/e22070718

Carbide Formation in Refractory Mo₁₅Nb₂₀Re₁₅Ta₃₀W₂₀ Alloy under a Combined High-Pressure and High-Temperature Condition

Entropy (Basel). 2020 Jun 28;22(7):718. doi: 10.3390/e22070718.

Authors

Congyan Zhang¹, Uttam Bhandari¹, Congyuan Zeng², Huan Ding², Shengmin Guo², Jinyuan Yan³, Shizhong Yang¹

Affiliations

¹ Department of Computer Science, Southern University and A&M College, Baton Rouge, LA 70813, USA.
² Department of Mechanical and Industrial Engineering, Louisiana State University, Baton Rouge, LA 70803, USA.
³ Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA.

Abstract

In this work, the formation of carbide with the concertation of carbon at 0.1 at.% in refractory high-entropy alloy (RHEA) Mo₁₅Nb₂₀Re₁₅Ta₃₀W₂₀ was studied under both ambient and high-pressure high-temperature conditions. The x-ray diffraction of dilute carbon (C)-doped RHEA under ambient pressure showed that the phases and lattice constant of RHEA were not influenced by the addition of 0.1 at.% C. In contrast, C-doped RHEA showed unexpected phase formation and transformation under combined high-pressure and high-temperature conditions by resistively employing the heated diamond anvil cell (DAC) technique. The new FCC_L1₂ phase appeared at 6 GPa and 809 °C and preserved the ambient temperature and pressure. High-pressure and high-temperature promoted the formation of carbides Ta₃C and Nb₃C, which are stable and may further improve the mechanical performance of the dilute C-doped alloy Mo₁₅Nb₂₀Re₁₅Ta₃₀W₂₀.

Keywords: compression deformation; diamond anvil cell; high-entropy alloy; high-pressure and high-temperature property; synchrotron x-ray diffraction.

Abstract

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