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

Abstract

Structure evolutions of rapidly quenched Al65Ni10Si25 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 Al9Ni2. The phase composition in the equilibrium state was observed as Al + Si + Al3Ni. A high-temperature phase of Al6Ni3Si 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.