Abstract
Elastic moduli, Vickers hardness and fracture toughness of borate glasses containing 33.3 mol% of alkaline metal oxides or alkaline earth metal oxides were studied. Elastic moduli (bulk modulus K, Young’s modulus E, shear modulus G and Poisson’s ratio ν) were related with mean atomic volume V as follows; K=k1Vf, E=k2Vg, G=k3Vh, 1+ν=k4Vj, where f=−1.30 and −1.59, g=−1.64 and −2.13, h=−1.68 and −2.24, and j=0.11 and 0.04 for alkaline metal and alkaline earth metal borate glasses, respectively. The f value obtained from relationship between bulk modulus and mean atomic volume was close to a theoretical value (f=−4⁄3). Vickers hardness HV was correlated with ion-oxygen attraction I. There was a linear relationship between fracture toughness KIC and young’s modulus E.
