High-strength titanium alloy nanopillars with stacking faults and enhanced plastic flow

Abstract

Through ex situ and in situ compression and tension tests of micrometer- and submicrometer-sized single crystal hexagonal close packed (HCP) Ti alloy pillars oriented for prismatic slip, we have observed that “smaller is stronger” and the larger samples exhibit obvious strain bursts. However, for extremely small samples, the plastic flow becomes much more stable both in compression and tension, mainly due to the emergence of a high density of basal stacking faults (SFs) driven by extremely high stress, which rarely appear in larger samples and bulk counterpart. This work demonstrates a recipe towards ultra-high strength (GPa level) nanoscale samples with continous plastic flow.