Glass transition behavior, crystallization kinetics, and microstructure change of Zr41Ti14Cu12.5Ni10Be22.5 bulk metallic glass under high pressure

Glass transition behavior, crystallization kinetics, and the microstructural change of Zr41Ti14Cu12.5Ni10Be22.5 bulk metallic glass (BMG) are studied in ambient, annealing, and high pressure conditions. Significant structural relaxation induced by preannealing and high pressure annealing has been observed in the BMG obtained with a low cooling rate. The experimental results indicate that the BMG contains a large amount of vacancy-like free volume. The relaxation results in the microstructural transformation from short-range order to medium-range order and significant effects on the subsequent glass transition and crystallization. The role of relaxation in the glass transition and the crystallization is phenomenologically explained. (C) 2000 American Institute of Physics. [S0021-8979(00)10719-4].