Influence of electron irradiation on self‐healing and thermal oxidation of SiC dispersed yttrium silicate composites

Abstract Electron irradiation‐induced acceleration of self‐healing and high‐temperature oxidation has been discovered in SiC/Y 2 Si 2 O 7 –Y 2 SiO 5 composites. Bulk samples were produced by pulsed electric current sintering. These samples were exposed to an electron beam from the pulsed intense relativistic electron beam accelerator with a beam energy of 2 MeV at irradiation doses of 10–40 kGy. The self‐healing and high‐temperature oxidation experiments were carried out at 1100–1300°C for 1–24 h in laboratory air. Electron irradiation significantly improved the self‐healing effectiveness. The closure of surface cracks was caused by the volume expansion of SiC via transformation to SiO 2 and the outward diffusion of Y 3+ ions. Electron irradiation also increased the thickness of the internally oxidized zone, formed by the inward diffusion of O 2− ions. Enhanced self‐healing and oxidation behavior were associated with defect formation induced by electron beam exposure, which facilitated the diffusion of ions within the crystal lattice.