Abstract
A TEM observation and an EDX analysis were carried out on interfaces between Ag-Cu-2wt% Ti alloy and three types of SiC containing B and C, BeO or Al2O3 as additives. They were brazed at temperatures of 850° or 950°C for 30 min. Interfacial structures of the specimens joined at 850°C were SiC (containing B+C)/TiC/Ti5Si3/brazing metal, SiC (containing Al2O3)/amorphous oxide/TiC/Ti5Si3/brazing metal and SiC (containing BeO)/brazing metal/TiC/Ti5Si3/brazing metal. The amorphous oxide disappeared in the specimen brazed at 950°C using the SiC containing Al2O3. The bonding strength of SiC containing Al2O3 with itself using the same brazing alloy was nearly the same with that of the SiC containing B and C, but interfacial strength between SiC containing BeO and the reaction layer was much lower. The difference in interfacial structure was discussed in terms of excess C in the SiC ceramics and changes in the diffusion coefficients of Si and C in SiC ceramics, those are influenced by the sintering additives.
