Ceramic repair agents for damaged CMC: Assessing repair performance

In this paper, a low-temperature fast-curing repair agent with metal and ceramic powders composite modified with liquid sodium silicate was developed, which was optimized by composition to have high mechanical properties. After fabricating U-notches to remove cracks, the repair tolerance of C f /SiC composites was investigated on the basis of relative residual flexural strength and notch depth, respectively. The fracture morphology of the repaired C f /SiC parent material showed that the repair agent could fill the pores between the fiber bundles of the parent material better, and restored the flexural strength of the parent material from 91.07 MPa to 142.04 MPa, with a restoration rate as high as 55.96 %. This study is expected to be applied to the low-cost and rapid repair of ceramic matrix composites to increase the possibility of their application in aero engines .