Structure and phase transformations of amorphous-nanocrystalline Al-based alloy

Abstract

Structure evolutions of rapidly quenched Al 65 Ni 10 Si 25 alloy were investigated using DTA, X-ray diffraction, SEM, and EDX methods. The processes of structural transformation from the as-quenched state into a nanocrystalline state were studied. The common and distinctive features of structural transformation processes induced by heating, isothermal annealing, and laser irradiation were observed. The formation of the nanoscale structure was observed in all ways of treatment. Two metastable phases that were formed at different temperatures were observed: hexagonal H-phase and Al 9 Ni 2 . The phase composition in the equilibrium state was observed as Al + Si + Al 3 Ni. A high-temperature phase of Al 6 Ni 3 Si was found in the alloy after laser heating that shows the possibility of "freezing" the high-temperature phases in the ribbon structure using laser treatment. The fractal structure was observed on the ribbon surface after irradiation.

Effect of laser remelting treatment on Al85Ni8Y4Ce3 amorphous coating

“…It is a new structural material with broad application prospects and has been paid close attention by researchers at home and abroad [4][5][6]. A large number of research results show that amorphous alloys can be formed as long as the cooling rate of the metal alloy system is greater than 10 6 K s −1 [7,8]. Owing to the limitation of the high critical cooling rate, the size of the amorphous samples prepared is small and thin, which limits the further development of amorphous alloys [9][10][11].…”