Influence of fine-scale B2 precipitation on dynamic compression and wear properties in hypo-eutectic Al0.5CoCrFeNi high-entropy alloy

Abstract The near equi-atomic high-entropy alloys based on Al, Co, Cr, Fe, Ni have provided a novel microstructural template for alloy design. The face centered cubic (FCC) matrix strengthened by body centered cubic (BCC) based ordered B2 precipitates can be used to develop new generation of precipitation strengthened alloys. The present study focuses on an Al0.5CoCrFeNi hypo-eutectic alloy consisting of an as-solidified FCC + B2 microstructure. Guided by solution thermodynamic modeling, this alloy has been isothermally aged for solid-state precipitation of a high fraction of fine scale intragranular B2 particles. While, the positive influence of B2 on tensile strength, and work hardenability have been published earlier, the current work presents effect of fine scale B2 phase on sliding wear and dynamic compression properties. The flow stress at 0.02% true strain increased from ∼670 MPa to ∼1350 (102%) MPa, the ultimate compressive strength increased from ∼1160 MPa to 1500 MPa (20%), and the wear resistance increased more than 5 times with progressively increasing phase fraction of B2 precipitates.