Probing pre-serration deformation in Zr-based bulk metallic glass via nanoindentation testing

Bulk metallic glasses (BMG) are promising candidates for structural applications. However, they exhibit catastrophic failure, and the detection of their incipient plastic response remains unclear. In this study, we investigated the incipient plastic deformation behavior in Zr50Cu40Al10 at% bulk metallic glass via nanoindentation testing. An original and validated analytical layout, which is based on the load-over-displacement versus the displacement P/h-h plot, facilitates the analysis of any unstable deformation mode in the loading segment of the nanoindentation test. A certain anelastic deformation was detected definitely prior to the first serration that is conventionally recognized as a plasticity initiation. This result clearly indicates the presence of a precursor phenomenon to incipient plasticity before the first serration in BMG.