Amorphous structure rejuvenation under cryogenic treatment of Al-based amorphous-nanocrystalline alloys

Effect of cryogenic treatment on amorphous phase rejuvenation in Al-based alloys was studied by X-ray diffraction, transmission and high-resolution electron microscopy. It was established that cryogenic cycling may lead to amorphization of nanocrystalline regions and amorphous phase rejuvenation in partially crystalline samples. The composition of nanocrystals in the investigated samples differed from that of amorphous phase, therefore, the process of amorphization under cryogenic cycling was accompinied by mass transfer. A degree of amorphization depends on the duration of cryogenic cycling and increases with an increase in its duration. Amorphization of a partially crystalline structure under cryogenic cycling is observed for nanocrystals formed under both heat treatment and deformation.