Hydrogen effect on the softening behavior of Zr-based bulk metallic glass

Abstract

As an effort to analyze the influnce of hydrogen on the plasticity of bulk metallic glasses (BMGs) we performed a series of instrumented macro- and nano-indentation experiments on the Zr-based BMG samples which were hydrogen-charged under a current density of a mA/cm2 for different time up to 200 h. First we examined the inhomogeneous plastic deformation of a Zr-based BMG by performing macroscopic instrumented indentation (with a spherical indenter) on the bonded-interfaces of the hydrogen-charged samples. The subsurface deformation of the charged sample was compared with that of non-charged samples. Subsequent performance of nanoindentation (with a Berkovich indenter) on the subsurface deformed regime revealed that both the hydrogen-charged and non-charged samples experienced the softening behavior during macro-indentation, but the characteristics and degree of the softening was significantly affected by the hydrogen charging time.