Influence of reduction ratio on the microstructural evolution and subsequent mechanical properties of cold-drawn Co10Cr15Fe25Mn10Ni30V10 high entropy alloy wires

摘要

Influence of multi-pass reduction on the microstructural evolution and subsequent mechanical properties of a senary non-equiatomic Co10Cr15Fe25Mn10Ni30V10 (atomic %) high-entropy alloy was investigated. HEA rods obtained from a Y-block casting were cut, caliber rolled, annealed, and then produced into wires with of varying diameters by cold drawing at room temperature. The maximum reduction ratio of 96% was successfully used to manufacture 1-mm diameter wire. This resulted in a maximum tensile strength of 1.6 GPa without breakage during cold drawing. Both electron back-scatter diffraction (EBSD) and transmission electron microscopy (TEM) examination revealed that nano-scale ultrafine grains and deformation twins were generated by the multi-step drawing process. This phenomenon suggests that nano-twinning rather than grain refinement is dominant mechanism required for achieving high-strength in the Co10Cr15Fe25Mn10Ni30V10 senary high entropy alloy. (C) 2019 Elsevier B.V. All rights reserved.