Enhanced mechanical performance and residual stress analysis of SiCf/SiC joints via reaction bonding with interconnected SiC nanowires network

The reliable joining of SiC f /SiC composites is crucial for manufacturing large and complex shaped components. In this work, a reliable joining of SiC f /SiC composites is successfully fabricated using the reactive bonding method by introducing SiC nanowires (SiCnws) and porous carbon skeleton. The interconnected SiCnws network enhances the structural stability of the joint, while the porous carbon skeleton promotes the infiltration of molten Si and provides the carbon source for in-situ SiC formation, resulting in a dense and defect-free microstructure of the joint. The microstructure and mechanical properties of the joints are systematically evaluated, and the joint exhibits a dense morphology free of pores and cracks, with a considerable shear strength of 32.23 MPa. The excellent mechanical performance can be attributed to the bridging and pulling out of SiCnws, which effectively dissipate the energy required for crack propagation and delay crack propagation. Additionally, the high compressive residual stress inside the joint helps to suppress crack propagation and improve the fracture resistance of the joint.