Effects of deep cryogenic treatment on the solid-state phase transformation of Cu–Al alloy in cooling process

The solid-state phase transformation temperature and duration of deep cryogenic treated and untreated Cu–Al alloys in cooling process were measured by differential scanning calorimetry measurement. The solid-state phase transformation activation energy and Avrami exponent were calculated according to these measurements. The effects of deep cryogenic treatment on the solid-state phase transformation were investigated based on the measurement and calculation as well as the observation of alloy's microstructure. The results show that deep cryogenic treatment can increase the solid-phase transformation activation energy and shorten the phase transformation duration, which is helpful to the formation of fine grains in Cu–Al alloy.