Indentation creep of a Ti-based metallic glass

In this work, the time-dependent plastic deformation behavior of Ti₄₀Zr₂₅Ni₃Cu₁₂Be₂₀bulk and ribbon metallic glass alloys was investigated using a nanoindentation technique at room temperature with the applied load ranging from 5 to 100 mN. The stress exponentn, defined as, has been derived as a measure of the creep resistance. It was found that the measured stress exponent increases rapidly with increasing indentation size, exhibiting a positive size effect. The size effect on the stress exponentnobtained from the bulk sample is more pronounced than that obtained from the ribbon sample. The deformation mechanism involved will be discussed.