Preparation of jointed composites with interconnected SiC nanowires network for nuclear SiC fiber reinforced SiC composites

The reliable jointing of SiC_f/SiC is considered to be a key factor limiting the application in the field of nuclear cladding. In this work, a jointing layer with interconnected SiC nanowires (SiCNWs) toughening network is prepared by a typical two-step routine. The high-viscosity slurry containing the precursor is pyrolyzed to form a porous SiC-based jointing layer, which is then densified by chemical vapor infiltration. Besides, SiC powders are introduced into the slurry to further increase the density of the jointing layer. The homogeneous SiC jointing material enables the strength and effectively avoids the mismatch between the thermal expansion coefficient of the jointing layer and SiC_f/SiC composites, and the apparent shear strength of the jointing specimen reaches 7.211 MPa. It is found that the joint with SiCNWs shows better shear strength than the joint without SiCNWs, and the improved mechanical properties could be attributed to the pull-out and bridging of SiCNWs.