In‐situ reactive joining of silicon carbide ceramics with zirconium disilicide and graphite

Abstract High‐strength joining of silicon carbide (SiC) ceramics was achieved at relatively low temperatures through in‐situ reaction of zirconium disilicide (ZrSi 2 ) and graphite (C), employed as the joining material. The effects of C content and joining temperature on the microstructure, phase composition, and mechanical properties of the joints were investigated. The interlayer was composed of SiC, zirconium carbide, ZrSi 2 , and Si‐Zr phases. The shear strength of the joint first increased and then decreased with the increase of C content. When the molar ratio of C/ZrSi 2 was 2, the shear strength measured of the joint, which was conducted at 1450°C by spark plasma sintering, was 178.2 ± 8.6 MPa. Subsequently, the C/ZrSi 2 powder with a molar ratio of 3 was employed to join SiC ceramics at different joining temperatures, and the shear strength of the joint was positively correlated with the joining temperature. The SiC joint achieved in this study offers great potential for application in extreme environments.