AbstractThe Ti‐coated Cf‐SiCf/SiBCN ceramic was diffusion‐bonded to Nb using an Ag–Pd interlayer. At a ceramic/Ag–Pd interface, it is found that Ti first reacted with C and Pd to form a TiCx/Ti(Pd) double‐layer structure, and then Ti(Pd) completely converted into TiCx with the increase of holding time or temperature. Meanwhile, the infiltration of Pd along TiCx grain boundary reacted with Si to form brittle Pd2Si compound. By contrary, only a simple NbPd3 layer was formed at the Nb/Ag–Pd interface during the whole process. A maximum shear strength of 16 ± 3 MPa is obtained for the joint prepared at 900°C for 30 min. The plastic deformation of the Ag–Pd interlayer and pullout of fibers inside ceramic contributed to the superior performance. Nevertheless, as the holding time and temperature reached 90 min and 950°C, the high chemical affinity of the Pd–Si system and enhanced atomic diffusion led to the massive formation of Pd2Si, which increased the joint brittleness and degraded the ceramic performance.