The mechanical response of multicomponent borosilicate glasses has drawn significant attention in the design of damage-resistant glasses. In this work, we investigate the plasticity of two borosilicate glasses, Borofloat®33 (Boro33) and N-BK7®, by implementing a uniaxial tension test using molecular dynamics simulations. A bond-switching mechanism is found to be responsible for the plastic response of both glasses and is governed by the increasing rate of non-bridging oxygen (NBO) production during the uniaxial tension. We found that the amount of B4OSi4 linkages in the glass governs the stress drop after yielding, due to its higher tendency to create NBOs compared to Si4OSi4. Also, the initial existence of NBOs weakens the critical stress for breaking the B4-O bond in B4OSi4, which in turn lowers the yield strength of the glass. The local atomic constraints are analyzed in the two glasses, and high anti-correlation between the concentration of rigid constraints and plastic deformation is observed.
All Science Journal Classification (ASJC) codes
- Ceramics and Composites
- Materials Chemistry