Rapid flash sintering method for localized repair of SiCf/SiC with foreign object damage

The rapid and efficient repair of ceramic matrix composite damaged by foreign objects is a significant technical challenge for extending the service life of aerospace components. In this study, a localized repair method combining gel casting and flash sintering technologies is proposed for repairing SiC f /SiC with penetration damage. The repair process involves the regularization of the damaged area using high-pressure water jet treatment, the construction of a scaffold via gel casting, and the achievement of localized densification and reinforcement through flash sintering. Experimental data demonstrate that the porosity of the repaired region is reduced from an initial 62.25–8.57 %, while the density is increased from 2.09 g/cm³ to 2.28 g/cm³. Additionally, the flexural strength of the repaired samples reaches 112.83 MPa, equivalent to 51 % of the original material's strength. This technique minimizes thermal damage, enhances precision, and provides a practical pathway for extreme remanufacturing of damaged ceramic matrix composites.