Abstract: Sintered silicon carbide was jointed with itself using Ag-Cu-In-Ti filler metal successfully. Interfacial microstructure was investigated by electron probe microanalysis (EPMA) and transmission electron microscope (TEM). Joining strength of SiC/SiC joints was measured by four-point flexural strength. The experimental results indicate that joining strength has a peak value with the joining temperature increasing, and the max flexural strength reaches 234MPa, however joining strength decreases monotonously with the holding time increasing. The interface of joints is composed of three parts: SiC substrate, reaction layer and filler metal. The continuous and compact reaction layer which is composed of strip layer, TiC layer and Ti₅Si₃ layer, combines the SiC substrate and filler metal tightly. The strip layer consisting of Ag, In, Si, Cu, Ti and C elements is about 20nm in thickness. The elemental linescanning result shows that nearly all the active element Ti concentrate in the reaction layer and the main reason for the joining is the reaction between Ti and SiC.

Key words: Ag-Cu-In-Ti, SiC, joining strength, interface structure