Difference in crystallization kinetics of Zr41Ti14Cu12.5Ni10Be22.5 bulk metallic glass under different oxidizing environments

Crystallization kinetics of Zr41Ti14Cu12.5Ni10Be22.5 bulk metallic glass (BMG) isothermally annealed at 653 K under different air pressures has been investigated using X-ray diffraction, transmission electron microscopy and X-ray photoelectron spectroscopy. The kinetics was found to have a strong dependence on the variation of the air pressure during annealing. The time required for the formation of crystals in detectable quantities under 5 Torr was about seven times shorter than that under 760 Torr. The accelerated crystallization in the former case is attributed to a large amount of oxygen penetrating into the BMG. The phenomenon is discussed on the basis of oxygen contamination under atmospheric annealing.