Towards damage resistant Al2O3–SiO2 glasses with structural and chemical heterogeneities through consolidation of glassy nanoparticles

Abstract

Al2O3–SiO2 binary glasses with structural and chemical heterogeneities were prepared by consolidating glassy nanoparticles with different compositions using classical molecular dynamics simulations. Consolidated glasses show both excellent ductility and enhanced flow strength. It was found that the structural heterogeneities such as over-coordinated network formers and neighboring oxygen induced during consolidation serve as plasticity carriers to increase the ductility. On the other hand, the enhanced yield strength in consolidated glasses is due to the chemical heterogeneity inherited from the starting glassy nanoparticles, which does not compromise the ductility. Furthermore, apparent work hardening behavior appears upon cold work in the consolidated glasses, with an increase in yield strength from ~3.3 to ~6.4 GPa after 40% cold work. Consolidation with glassy nanoparticles could be a viable way to synthesize strong, damage resistant and transparent oxide glasses that cannot be obtained through the traditional melt-quench process.