SILICA and its process zone

International audienceThis article reviews recent works concerning the damage area size ahead of a crack front in oxide glasses. Literature exemplifies the importance of understanding the crack propagation dynamics in oxide glasses with a number of papers concerning dynamic and stress corrosion cracking in complex (and simplified) oxide glasses. In general, the linear elastic fracture mechanic equation breaks down near the crack front, in a zone frequently called the process zone. The question is how large is this zone near the crack tip? This paper reviews four different techniques to capture the process zone size in pure silica: Atomic force microscopy imaging, neutron diffraction, photon capture, and molecular dynamics simulations. Velocities of the crack front range between stress corrosion cracking dynamics and dynamic fracture, thus providing a better understanding of how the process zone depends on the velocity of the crack front