Study of crystallization mechanism of Al-based amorphous alloys by in-situ high temperature X-ray diffraction method

Abstract The role of transition metals (TMs) addition on the formation and crystallization of amorphous Al 85 TMs 10 Y 5 alloys was described using in-situ high-temperature X-ray diffraction. The structural results were compared with differential scanning calorimetry and dynamical mechanical analysis to obtain detailed information about the nucleation and growth of crystalline phases. The performed analysis confirmed that Fe and Cu addition drastically changes the crystallization temperature and the phase composition of the fully crystallized alloys. While for Al 85 Ni 10 Y 5 alloy, the second crystallization step is related to the formation of Al 19 Ni 5 Y 3 phase, for Al 85 (Ni, Fe) 10 Y 5 and Al 85 (Ni, Fe, Cu) 10 Y 5 alloys crystallization of Al 15 Fe 9 Y 2 phase was observed. Interestingly, the performed analysis showed that forming a homogenous amorphous phase is not necessary to obtain the best corrosion resistance. It was noted that the precipitation of the YCr 2 Al 20 phase in the Cu-rich amorphous matrix should be a much more interesting approach.