The microstructure and mechanical performance of C/C-SiCf/SiC composite joints brazed by Si-10Zr eutectic alloy

The real-time wetting behavior of the Si-10Zr (at. %) eutectic alloy over the SiCf/SiC composites was investigated for the first time. The brazing of C/C composites and SiCf/SiC composites using the Si-10Zr filler alloy under a range of time was studied. The interfacial microstructure between the liquid alloy and the SiCf/SiC composites was determined. The joint microstructure, mechanical performance, and fractures of the C/C and C/C-SiCf/SiC joints were analyzed. The Si-Zr melt showed a contact angle of only 10 & DEG; at 1480 celcius, owing to good wettability and abundant infiltration into the porous SiCf/SiC composites. With the extension of holding time, the Si-10Zr alloy reacted with the two substrates and formed SiC interfacial layers. An optimal fracture mode combined the Si-ZrSi2 filler, composites, and the SiC reaction layers.