Evolution of the Al85Ni5Fe7La3 Amorphous Alloy Structure under Flash Lamp Annealing

Resumo

The microstructure of Al₈₅Ni₅Fe₇La₃ amorphous alloy after high-speed quenching, isothermal annealing, and flash lamp annealing (FLA) was studied by electron microscopy (including the high-resolution transmission electron microscopy), electron and X-ray diffraction, energy-dispersive X-ray microanalysis, and differential scanning calorimetry. A comparative analysis of the structures with respect to phase composition and phase morphology was performed. It was shown that, after the quenching, an X-ray amorphous structure is formed in the alloy. Critical parameters of heat treatment of the amorphous alloy which lead to single-phase or multiphase crystallization and volumetric or gradient structure were determined. The phase composition of the nanocomposite formed during crystallization was determined. The identity of the emerging structures with respect to the phase composition and phase morphology was determined for certain parameters of isothermal and flash lamp annealing to which close values of microhardness significantly exceeding the hardness of the alloy in the amorphous state correspond.