Revealing the mechanical behavior of homogeneous dislocation cell units in high-entropy alloy

Abstract

Gradient dislocation cell structured Al0.1CoCrFeNi high-entropy alloys exhibited exceptional strength and uniform ductility. HEA containing homogeneous dislocation cells, with the average size varying from 0.29 to 0.43 μm was observed to still exhibit a superior combination of high strength and good uniform elongation, distinct from traditional strong ultrafine-grained structures with limited ductility. This is because the initial dislocation cells tend to be progressively patterned into dense dislocation walls upon straining, associated with the massive dislocation motion and accumulation. The gradient-induced additional strain hardening behavior was clarified by directly comparing the mechanical behavior of the homogeneous and gradient samples.IMPACT STATEMENT Both high strength and good ductility can be simultaneously achieved in homogeneous ultrafine-sized dislocation cell, distinct from traditional strong, yet less ductile ultrafine-grained structures.

Keywords

• HEA
• homogeneous dislocation cell
• deformation behavior
• strain hardening