Scaling exponents for fracture surfaces in homogenous glass and glassy ceramics

Daniel Bonamy (1) , Laurent Ponson (1) , Silke Prades (1) , Elisabeth Bouchaud (1) , Claude Guillot (1)

1 SPCSI - Service de Physique et de Chimie des Surfaces et Interfaces

We investigate the scaling properties of post-mortem fracture surfaces in silica glass and glassy ceramics. In both cases, the 2D height-height correlation function is found to obey Family-Viseck scaling properties, but with two sets of critical exponents, in particular a roughness exponent $\zeta\simeq 0.75$ in homogeneous glass and $\zeta\simeq 0.4$ in glassy ceramics. The ranges of length-scales over which these two scalings are observed are shown to be below and above the size of process zone respectively. A model derived from Linear Elastic Fracture Mechanics (LEFM) in the quasistatic approximation succeeds to reproduce the scaling exponents observed in glassy ceramics. The critical exponents observed in homogeneous glass are conjectured to reflect damage screening occurring for length-scales below the size of the process zone.

Mots clés: fracture; roughening; fractal cracks

Domaines: Mécanique statistique [cond-mat.stat-mech]; Mécanique des solides [physics.class-ph]; Mécanique des solides [physics.class-ph]

Daniel Bonamy, Laurent Ponson, Silke Prades, Elisabeth Bouchaud, Claude Guillot. Scaling exponents for fracture surfaces in homogenous glass and glassy ceramics. Physical Review Letters, 2006, 97 (13), pp.135504. ⟨10.1103/PhysRevLett.97.135504⟩. ⟨hal-00089020⟩