Calculation and construction of deformation mechanism maps and processing maps for CoCrFeMnNi and Al0.5CoCrFeMnNi high-entropy alloys

Abstract

Though extensive studies have been performed on high entropy alloys, there is still a lack of understanding of their high-temperature deformation mechanisms. By systematically analyzing the high-temperature behavior of fine-grained and coarse-grained CoCrFeMnNi and Al0.5CoCrFeMnNi high-entropy alloys (HEAs) studied in this work and reported in the literature, their constitutive deformation equations for dislocation climb creep, grain boundary sliding, and solute drag creep were determined. Based on the identified deformation mechanism equations, deformation mechanism maps and processing maps for CoCrFeMnNi and Al0.5CoCrFeMnNi alloys could be calculated and constructed. Ultimately, the processing maps could be combined with deformation mechanism maps in 2D or 3D. The proposed maps will be useful in predicting the optimum hot working conditions at various grain sizes and in different operating temperature and strain-rate ranges as well as identifying the deformation mechanisms at the corresponding conditions. The same approaches can be used for calculating the deformation mechanism and processing maps for other HEAs with different crystal structure and compositions. (C) 2021 Elsevier B.V. All rights reserved.