Cryogenic mechanical behavior of CoCrFeNi alloy at different stages of recrystallization

The microstructure and cryogenic mechanical properties have been investigated in a CoCrFeNi alloy cold rolled to 95% thickness reduction and subsequently annealed to produce either partially recrystallized or fully recrystallized samples. A combination of high yield strength (1 GPa), high ultimate tensile strength (1.4 GPa), and good ductility (42%) is obtained at − 196°C in a sample with a recrystallized area fraction of 62%. It is demonstrated that plastic deformation at this temperature results in profuse twinning within recrystallized grains. The strength and ductility of each cryogenically tested sample are found to be higher than those at room temperature.