Evaluation of elastic/mechanical properties of some glasses and nanocrystallized glass by cube resonance and nanoindentation methods

Elastic and mechanical properties of 10La₂O₃·30Bi₂O₃·60B₂O₃ (LaBiB) glass, 15K₂O·15Nb₂O₅·68TeO₂·2MoO₃ (KNbTeMo) glass and a transparent KNbTeMo nanocrystallized (particle size: ∼40 nm) glass were examined using cube resonance and nanoindentation methods. The values of Poisson’s ratio, Young’s modulus (E), Debye temperature (θ_D), fractal bond connectivity, Martens hardness, indentation hardness, indentation Young’s modulus, elastic recovery, Vickers hardness, fracture toughness (K_c) and brittleness for the samples were evaluated, and the relation with the structure and nanocrystallization were clarified. LaBiB glass containing high oxygen-coordinated La³⁺ ions and two-dimensional BO₃ structural units shows excellent properties of E=90.6 GPa, θ_D=404 K and K_c=0.72 MPa m^1/2 and a high resistance against deformation during Vickers indentation. KNbTeMo glass with the three-dimensional network structure and consisting of weak Te-O bonds has small values of E=51.4 GPa and K_c=0.29 MPa m^1/2. It was demonstrated that the elastic and mechanical properties of KNbTeMo precursor glass are largely improved by nanocrystallization, e.g., E=69.7 GPa and K_c=0.32 MPa m^1/2. The nanocrystallization also induces a high resistance against deformation during Vickers indentation.