Metallurgical and Materials Transactions A

, Volume 47, Issue 7, pp 3306–3311

Entropy and Diffuse Scattering: Comparison of NbTiVZr and CrMoNbV

Symposium: High Entropy Alloys III

DOI: 10.1007/s11661-015-3095-x

Cite this article as:
Widom, M. Metall and Mat Trans A (2016) 47: 3306. doi:10.1007/s11661-015-3095-x
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Abstract

The chemical disorder intrinsic to high-entropy alloys inevitably creates diffuse scattering in their X-ray or neutron diffraction patterns. Through first principles hybrid Monte Carlo/molecular dynamics simulations of two BCC high-entropy alloy forming compounds, CrMoNbV and NbTiVZr, we identify the contributions of chemical disorder, atomic size, and thermal fluctuations to the diffuse scattering. As a side benefit, we evaluate the reduction in entropy due to pair correlations within the framework of the cluster variation method. Finally, we note that the preference of Ti and Zr for hexagonal structures at low temperature leads to a mechanical instability reducing the local BCC character of NbTiVZr, while preserving global BCC symmetry.

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© The Minerals, Metals & Materials Society and ASM International 2015

Authors and Affiliations

  1. 1.Department of PhysicsCarnegie Mellon UniversityPittsburghUSA