Nanohardness and elastic anisotropy of ZrB2 crystals

Room temperature instrumented nano-indentation with a Berkovich tip was carried out on polycrystalline ZrB2. The orientation of the individual grains was mapped using electron backscattered diffraction. The anisotropy in properties was ∼20% and ∼7% for nanohardness and indentation modulus, respectively. The nanohardness decreased from basal towards prismatic orientation with a minimum at ∼50–60° and the indentation modulus increased with a maximum at ∼70–80°. The indentation modulus anisotropy, calculated by Vlassak-Nix model, shows similar tendency as the experimental values.