Characterizing the Soldering Alloy Type In-Ag-Ti and the Study of Direct Soldering of SiC Ceramics and Copper

The aim of the research was to characterize the soldering alloy In-Ag-Ti type, and to study the direct soldering of SiC ceramics and copper. The In10Ag4Ti solder has a broad melting interval, which mainly depends on its silver content. The liquid point of the solder is 256.5 degrees C. The solder microstructure is composed of a matrix with solid solution (In), in which the phases of titanium (Ti3In4) and silver (AgIn2) are mainly segregated. The tensile strength of the solder is approximately 13 MPa. The strength of the solder increased with the addition of Ag and Ti. The solder bonds with SiC ceramics, owing to the interaction between active In metal and silicon infiltrated in the ceramics. XRD analysis has proven the interaction of titanium with ceramic material during the formation of the new minority phases of titanium silicide-SiTi and titanium carbide-C5Ti8. In and Ag also affect bond formation with the copper substrate. Two new phases were also observed in the bond interphase-(CuAg)(6)In-5 and (AgCu)In-2. The average shear strength of a combined joint of SiC-Cu, fabricated with In10Ag4Ti solder, was 14.5 MPa. The In-Ag-Ti solder type studied possesses excellent solderability with several metallic and ceramic materials.