Discussion on the Structural Origins of the Fracture Toughness and Hardness Changes in Rapidly Quenched Borosilicate Glasses: A Molecular Dynamics Study

摘要: Abstract Understanding radiation effects in nuclear glasses is important order to assess their long term behaviour a geological repository. In this paper, the results obtained by classical molecular dynamics about mechanical properties of simplified SiO 2 – B O 3 Na glass with same molar proportions as real French were reviewed. A pristine and disordered structure, representative irradiated one, prepared address question on fracture toughness hardness. first step, simulations performed compare atomistic mechanisms glasses. second nanoindentation was simulated using diamond tip again behaviors compared. The depolymerisation associated disordering, particular increase tri-coordinated boron concentration relative tetra-coordinated improves resistance favouring plastic flows. On contrary, swelling limits facilitating cavity formation. effect dominant case investigated here because, experimentally, increases after irradiation. Concerning hardness, both decrease coordination parallel non-bridging oxygen formation free volume accumulation lead hardness because more open structure facilitates penetration.