High Strain-Rate Nanoindentation Testing of Single-Crystal FCC and BCC Metals

A new nanoindentation instrument capable of capturing the displacement of an indenter and the load on a sample during a dynamic indentation event has been used to explore deformation behavior at high indentation strain-rates up to 10⁴ s^-1in single-crystal FCC and BCC metals. In general, the hardness of the materials is observed to increase at the higher strain-rates. Three-dimensional imaging of the residual impressions formed dynamically at high indentation strain-rates are directly compared to those obtained under quasi-static conditions revealing differences in contact geometry and pile-up that help to explain the origin of the increased hardness and demonstrate the accuracy of a newly applied experimental methodology for hardness measurement at high strain-rates.