On sintering of tiny glass beads in oscillating diametric compressions

Abstract

Sintering of tiny spherical glass beads induced by oscillating diametric compression at room temperature is considered. The amorphous glass beads are modeled as isotropic elasto-plastic solid with bilinear stress-strain constitutive relationship, which is implemented in a finite element code. The coupled thermal and mechanical response of the glass beads under cyclic compressions is investigated. Our numerical simulations show that the local temperatures and stresses near the contact points can significantly be raised during adiabatic compression cycles. The temperature rise is more pronounced for contact between two beads with different sizes or for contact with more neighboring beads. There exist temperature and stress gradients from the interiors toward the contact points. These findings provide a feasible explanation for the sintering found in recent triaxial compression experiments with tiny glass beads under room temperature and low pressure.