Microstructure evolution and composition redistribution of FeCoNiCrMn high entropy alloy under extreme plastic deformation

Abstract

The microstructure and composition evolution of FeCoNiCrMn high entropy alloy during extreme deformation with a strain rate of 108–109 s−1 induced by cold spray technology was investigated. In the region experiencing extremely large strain and high strain rate deformation, ultrafine nanograins with an average size of smaller than 100 nm were formed due to the occurrence of dynamic recrystallization. Additionally, the rapid redistribution of segregated Mn and Ni elements in extremely deformed FeCoNiCrMn was found for the first time. The reason for this phenomenon is the increased grain boundary area and dislocation density caused by extreme plastic deformation.

Keywords

• high entropy alloy
• ultra-high strain rate
• severe plastic deformation
• cold spray