Self‐healing processing in SiO₂‐AlB₂ and SiO₂‐SiB₄ glass composites for high‐temperature applications

AlB 2 and SiB 4 are used as active particles to design model SiO 2 ‐20 vol.% active particles composites for high‐temperature applications. The oxidation of AlB 2 and SiB 4 particles in air at T = 1000°C–1050°C rapidly leads to the formation of an important quantity of liquid that can heal cracks. Model composites have been used to determine liquid flowing speed into the cracks and to discuss the effect of liquid properties, such as viscosity and wettability, on healing efficiency. The main role of the secondary reaction of the liquid with the matrix to form a dense solid‐state compound, from which crack healing stabilization is expected, is underlined.