Residual thermal stress of SiC/Ti 3 SiC 2 /SiC joints calculation and relaxed by postannealing

Abstract Residual thermal stresses in SiC/Ti 3 SiC 2 /SiC joining couples were calculated by Raman spectra and simulated by finite element analysis, and then relaxed successfully by postannealing. The results showed that the thermal residual stress between Ti 3 SiC 2 and SiC was about on the order of 1 GP a when cooling from 1300°C to 25°C. The thermal residual stresses can be relaxed by the recovery of structure disorders during postannealing. When the SiC/Ti 3 SiC 2 /SiC joints postannealed at 900°C, the bending strength reached 156.9 ± 13.5 MP a, which was almost twice of the as‐obtained SiC/Ti 3 SiC 2 /SiC joints. Furthermore, the failure occurred at the SiC matrix suggested that both the flexural strength of joining layer and interface were higher than the SiC matrix.