Discrete deformation in amorphous metals: an in situ SEM indentation study

Abstract

The formation of shear-bands in a Zr-based bulk metallic glass (Vitreloy-105) was investigated via in situ scanning electron microscopy (SEM) micro-indentation experiments. The formation of new shear-bands was correlated with displacement bursts visible in the load–displacement data. Surface steps around residual indents are often the result of multiple shear-band reactivations at the same locations. Partial crystallization does not stabilize the deformation process, but leads to further strain localization. Higher loading rates lead to smooth load–displacement curves and, in the case of partially crystallized specimens, continuous shear-band activity was detected.

Acknowledgments

The authors would like to thank J.-M. Breguet and R. Rabe for the design of the in situ indentation system. Support from the Swiss National Science Foundation (Grant# 200021-108071) and from start-up funds from the ETH Zürich are gratefully acknowledged (J.F.L.). B.M. acknowledges financial support by the Swiss State Secretariat for Education and Research, European Project FP6-NMP MASMICRO.