HAL will be down for maintenance from Friday, June 10 at 4pm through Monday, June 13 at 9am. More information
Skip to Main content Skip to Navigation
Journal articles

Thermal activation parameters of plastic flow reveal deformation mechanisms in the CrMnFeCoNi high-entropy alloy

G. Laplanche J. Bonneville 1 C. Varvenne 2 W. A. Curtin E. P. George
1 PDP - Physique des Défauts et de la Plasticité PDP
Département Physique et Mécanique des Matériaux - Département Physique et Mécanique des Matériaux
Abstract : To reveal the operating mechanisms of plastic deformation in an FCC high-entropy alloy, the activation volumes in CrMnFeCoNi have been measured as a function of plastic strain and temperature between 77 K and 423 K using repeated load relaxation experiments. At the yield stress, sigma(y), the activation volume varies from similar to 60 b(3) at 77 K to similar to 360 b(3) at 293 K and scales inversely with yield stress. With increasing plastic strain, the activation volume decreases and the trends follow the Cottrell-Stokes law, according to which the inverse activation volume should increase linearly with sigma - sigma(y) (Haasen plot). This is consistent with the notion that hardening due to an increase in the density of forest dislocations is naturally associated with a decrease in the activation volume because the spacing between dislocations decreases. The values and trends in activation volume agree with theoretical predictions that treat the HEA as a high-concentration solid-solution-strengthened alloy. These results demonstrate that this HEA deforms by the mechanisms typical of solute strengthening in FCC alloys, and thus indicate that the high compositional/structural complexity does not introduce any new intrinsic deformation mechanisms. (C) 2017 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.
Complete list of metadata

Contributor : Hal Cinam Connect in order to contact the contributor
Submitted on : Friday, January 19, 2018 - 9:36:50 AM
Last modification on : Wednesday, November 3, 2021 - 6:35:17 AM

Links full text




G. Laplanche, J. Bonneville, C. Varvenne, W. A. Curtin, E. P. George. Thermal activation parameters of plastic flow reveal deformation mechanisms in the CrMnFeCoNi high-entropy alloy. Acta Materialia, Elsevier, 2018, 143, pp.257-264. ⟨10.1016/j.actamat.2017.10.014⟩. ⟨hal-01688044⟩



Record views