Brazing of C/C Composites and Ni Base Alloys with Fe-Base Brazing Filler Alloys

Carbon/Carbon composites have high specific strength and high heat resistance. To utilize its high heat resistance, it has been brazed to the heat resistance alloys using Ni-base brazing alloys. In this research, the feasibility of Fe-base brazing filler alloys to the brazing of C/C composites and Ni-base heat resistance alloys is investigated. A single lap brazed specimen is formed using a Hastelloy slab and a C/C composites slab. The Fe-base brazing filler has the composition of Fe-20Cr-42-Ni-12(Si+P), whose brazing temperature is 990-1050ºC. The brazing is conducted in the vacuum chamber which is heated with Joule heating of SiC (SILICONIT). The brazing temperature is 1000ºC and keeping time is 300s. For the obtained brazed joint the shear fracture test is conducted. Most of the joints are fractured inside of C/C composites. The microstructure of the brazed interface was observed using the optical microscope and SEM. Those observations revealed the formation of SiC on the C/C composites side. And relatively severe infiltration of brazing filler alloys into the C/C composites was observed.