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arXiv · 1803.06771

Tuning phase-stability and short-range order through Al-doping in (CoCrFeMn)100-xAlx high entropy alloys

Prashant Singh·Amalraj Marshal·Andrei V. Smirnov·Aayush Sharma·Ganesh Balasubramanian·K. G. Pradeep·Duane D. Johnson
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Abstract

For (CoCrFeMn)$_{100-x}$Al$_{x}$ high-entropy alloys, we investigate the phase evolution with increasing Al-content (0 $\le$ x $\le$ 20 at.%). From first-principles theory, the Al-doping drives the alloy structurally from FCC to BCC separated by a narrow two-phase region (FCC+BCC), which is well supported by our experiments. We highlight the effect of Al-doping on the formation enthalpy and electronic structure of (CoCrFeMn)$_{100-x}$Al$_{x}$ alloys. As chemical short-range order (SRO) in multicomponent alloys indicates the nascent local order (and entropy changes), as well as expected low-temperature ordering behavior, we use thermodynamic linear-response within density-functional theory to predict SRO and ordering transformation and temperatures inherent in (CoCrFeMn)$_{100-x}$Al$_{x}$. The predictions agree with our present experimental findings, and other reported ones.

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Prashant Singh, Amalraj Marshal, Andrei V. Smirnov, Aayush Sharma, Ganesh Balasubramanian, K. G. Pradeep, Duane D. Johnson. 2018-03-19. Tuning phase-stability and short-range order through Al-doping in (CoCrFeMn)100-xAlx high entropy alloys. https://doi.org/10.1103/physrevmaterials.3.075002

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