Fracture toughness of Ca-, Sr-, and Ba-aluminoborosilicate glasses

The field strength effect on fracture toughness was tested for three alkaline earth (AE) aluminoborosilicate (ABS) glasses. This work explores the impact of modifier field strength (FS) on macro-mechanical properties in line with previous works which examined the FS effect on structure, hardness, crack resistance, and elastoplastic properties of alkali and AE-ABS glasses. Fracture toughness (K_Ic^VNB) was found to increase as modifier FS increased; and the elastoplastic ratio (H_V/E) correlated well with plasticity, hardness, and fracture toughness. The purpose of this work is to examine the mechanical response of AE-ABS glasses at a larger length scale in order to determine whether the field strength effect is active as was observed at lower length scales in previous works. The observed increase and decrease of the K_Ic^VNB and H_V/E, respectively, with increasing modifier FS, suggest a strong correlation between increasing fracture toughness and crack resistance with increasing plasticity for the AE-ABS glasses studied.