Development of Cu-Sn or Cu-Zn Filler Metal for Joining Ceramics(Materials, Metallurgy & Weldability)

SiC was brazed to SiC using Cu-Sn-Ti filler metals with low melting points. At a constant Sn content of 16.5 at% the strength of the SiC/SiC joint brazed at 1123K in vacuum shows a maximum at 5.6 at%Ti, and decreases with an increasing content of Ti in the alloys. The fine TiC and Ti_5Si_3 precipitates distribute densely at the SiC/the alloy interface. The excess amounts of Sn and Ti in at% the alloys form a brittle intermetallic of CuSn_3Ti_5 in the joining layer of SiC/SiC, and affect the strength of the joint. SiC was also brazed to SiC using Cu-30at%Zn-Ti at the low brazing temperature of 1223K in vacuum.