Influence of the Active Particles on the Self‐Healing Efficiency in Glassy Matrix

Abstract In the present paper, we present the influence of the composition of the active particles on the self‐healing property in glass–particles (B, B₄C, VB, V, or VC) composites. The thermogravimetric curves and oxidation kinetics at 700 °C of the active particles are reported. We show that the oxidation rate is higher with vanadium‐based particles than with boron‐base ones, mainly due to the formation of B₂O₃ that acts as a diffusion barrier to oxygen. In situ healing of cracks in composites was observed using high‐temperature environmental scanning electron microscopy (HT‐ESEM). The composition of the phases formed by reaction between the oxidation products and the glassy matrix is systematically determined. Self‐healing occurs as a consequence of oxidation of active particles, which leads to the formation of an oxide, such as V₂O₅ and/or B₂O₃ that is fluid enough to fill in the crack at high temperature. The crack healing is obtained whatever the nature of the active particle.