Cold rolling deformation and recrystallization behavior of martensite Ni_40.5Co_32.5Al₂₇ alloy

The cold rolling deformation ability of martensite Ni_40.5Co_32.5Al₂₇ alloy was evaluated, and its cold rolling microstructure and recrystallization behavior were investigated by metallography and micro hardness methods. It is found that martensite based Ni_40.5Co_32.5Al₂₇ alloy exhibits excellent cold workability with a cold rolling critical reduction ratio of 46.2%-46.9%. Excellent compatibility in shape changes of martensite β′ phase and ductile y phase results in free of cracks in their interface after heavy cold rolling. Strong recovery process happens in the temperature range of 1073 K-1173 K and completed recrystallized process takes place at 1273 K for cold rolling Ni_40.5Co_32.5Al₂₇ alloy. The volume fraction of y phase decreases with the increasing of quenched temperature and martensitic β′ grains grow at the same process.