Delayed plasticity during nanoindentation of single-phase CoCrFeMnNi high-entropy alloy

Abstract

Spherical nanoindentation was performed at room temperature to characterize the time-dependent plasticity behavior of the single-phase CoCrFeMnNi high-entropy alloy (HEA). It was observed that incipient plasticity occurred after a period of waiting time in the apparent elastic regime. Through the experimental data, an activation energy ∼0.74 eV and an activation volume ∼1.54b3 (b = Burgers vector) were extracted for the delayed plasticity. Our results indicate that heterogeneous dislocation nucleation governs the delayed plasticity in the single-phase CoCrFeMnNi, and also provide quantitative insights into viscoplastic behavior and creep mechanisms in HEAs.

Keywords

• High-entropy alloys
• nanoindentation
• delayed plasticity
• dislocation nucleation