The structural relaxation study of Zr–Cu–Ni–Al metallic glass during heating by small-angle X-ray scattering

Zr${}_{65}$Cu${}_{17.5}$Ni${}_{10}$Al${}_{7.5}$ and Zr${}_{69.5}$Cu${}_{12}$Ni${}_{11}$Al${}_{7.5}$ alloys exhibit different crystallization features during heating. Zr${}_{65}$Cu${}_{17.5}$Ni${}_{10}$Al${}_{7.5}$ alloy undergoes one-step crystallization with formation of compounds of Zr${}_2$Cu and Zr${}_2$Ni, while Zr${}_{69.5}$Cu${}_{12}$Ni${}_{11}$Al${}_{7.5}$ alloy follows two-step crystallization with a preferential formation of quasi crystalline mesophase. In situ small-angle X-ray scattering was employed to investigate the structural relaxation of the both BMGs. The obtained results show that there is homogenization of density fluctuation in the transition from CSRO to TSRO in the process of isothermal annealing, and that the transition holding time decreases with increase of the annealing temperature, and that Zr${}_{69.5}$Cu${}_{12}$Ni${}_{11}$Al${}_{7.5}$ alloy has longer density fluctuation rising time and longer transition holding time than those Zr${}_{65}$Cu${}_{17,5}$Ni${}_{10}$Al${}_{7.5}$ alloy has.