Phase separation and nanocrystallization in Al₉₂Sm₈ metallic glass

International audienceCrystallization of Al92Sm8 metallic glass was investigated in-situ using combined small-angle and wide-angle X-ray scattering (SAXS/WAXS) techniques during isothermal annealing at temperatures close to crystallization point. A continuously growing interference maximum shifting progressively toward lower angles was found to develop in SAXS regime. Simultaneously taken WAXS spectra reveal formation of fcc-Al nanocrystalline phase. The analysis of the SAXS/WAXS data indicate that amorphous phase separation is responsible for the nanocrystalline microstructure formation. The primary fcc-Al crystals nucleate inside the Al-rich amorphous regions formed during alloy decomposition and their growth is constrained by the region size