Grain Refinement in High-Entropy Alloys by High-Pressure Torsion Deformation

Abstract

This article describes the process of grain refinement behavior in fcc high-entropy alloys (HEAs) by severe plastic deformation using high-pressure torsion (HPT) method. Disk samples of CrMnFeCoNi and Al_0.3CrFeCoNi were deformed by HPT. It was revealed that the two HEAs exhibit formation of equiaxed nanograins even after relatively low degree of deformation. Formation of fine lamellar structures by nanotwins or shear bands may be an important factor to drastically increase dislocation density, which leads to the formation of equiaxed nanograins by continuous dynamic recrystallization.