Mechanical properties and structural evolution of sodium borosilicate glasses during uniaxial tension: Molecular dynamics simulation and experiments

The mechanical properties and structural evolution of sodium borosilicate glasses under the uniaxial tensile process were investigated through molecular dynamics simulation. The simulated properties of sodium borosilicate glasses were in good agreement with the experimental values. [BO₃] and Na⁺ compensated [BO₄] groups were generated in the glass network in low boron content, while [BO₃] appeared with increasing boron oxide. The structure descriptor, F_net synthesized the structure and energy information of the glass network which was positively correlated with Young's modulus. The strength has been diminished due to the decreased degree of polymerization of the glass network and the migration of Na⁺ cations. Simultaneously, the elastic deformation of sodium borosilicate glass arose from the motion of Na⁺ cations and alterations in the Si-O-Si bond angle. Moreover, the plastic deformation of sodium borosilicate glasses was attributed to the transition from [BO₄] to [BO₃] and the higher mobility of [BO₃] than [BO₄] and [SiO₄].