Development of nanocrystals in an amorphous alloy Zr₄₇Ni₃₀Ti₂₃

Development of nanocrystals during crystallization of an amorphous alloy Zr₄₇Ni₃₀Ti₂₃ is studied using differential scanning calorimetry (DSC), X-ray diffraction (XRD) and high resolution transmission electron microscopy (HRTEM). Up on heating the amorphous ribbon in DSC, three exothermic peaks including a broad peak are observed. Stable nanocrystals embedded in the amorphous matrix form through primary crystallization. The nanocrystals have uniform sizes after prolonged annealing at 400°C for 180 minutes. Ni plays an important role for the stability of the nanocrystals. Due to the Ni partitioning between the nanocrystals and the residual matrix, the crystallization temperature (T_xl) of the residual amorphous matrix increases as crystallization proceeds. The formation of nanocrystal-amorphous composites that have high microstructural stability is possible through the controlled crystallization of the amorphous alloy Zr₄₇Ni₃₀Ti₂₃.