The effect of high strain rate impact in Yttria stabilized zirconia

Abstract

Yttria stabilized zirconia (6-8YSZ) is widely used as a top coat in Thermal Barrier Coatings (TBCs) to protect metallic substrates. These coatings are exposed to severe high strain rate fields along their life, for example during the impact of debris happening in service or during coating removal in repair processes. In this work a water jet and a high strain rate nanoindenter are used to understand the effect of the strain rate (from 10-3 to 108 s−1) on the behaviour of 8YSZ at a small scale. It is observed how, at extremely high strain rates (106–108 s−1), the material suffers from a brittle-dominated failure which induces localized phase transformation. At lower strain rates (10-3−1 s−1), plasticity dominates, and phase transformation is not observed.