Fabrication and microstructural study of oxide-dispersion strengthened CoCrFeMnNi high-entropy alloy via cryo-milling

Abstract

High Entropy Alloys (HEAs) have higher configuration entropies than conventional alloys because they have more than 5 metallic elements as principal elements with an equiatomic or near equi-atomic ratio. The high configuration entropy makes HEAs form a simple solid solution phase such as BCC or FCC. HEAs are promising candidates for industrial structural materials due to their excellent mechanical properties. Despite the excellent mechanical properties, it is needed to apply various strengthening mechanisms to HEAs in order to broaden the application area of HEAs by improving its mechanical properties. In this study, CoCrFeMnNi HEAs with 0.5 wt% of $Y_2O_3$ were fabricated to make an oxide dispersion strengthened (ODS) HEA. ODS-HEA powder particles were prepared under various process conditions. To investigate the effects of milling and sintering process parameters, the microstructural analysis of powder and sintered bulk samples was conducted. A small angle neutron scattering (SANS) analysis was conducted to perform the statistical analysis of nano-sized oxide particles in ODS-HEA powder and sintered bulk samples under various cryo-milling and heat treatment