Interface structure and mechanical property of the brazed joint of graphite and copper

A kind of self-made AgCuTiSn braze alloy powder was used to join graphite and copper. The whole brazing process was performed under vacuum circumstances at different temperatures (1033-1193 K) for several holding time (300-1800 s). According to scanning electron microscope (SEM), energy dispersive spectrometer (EDS) and electron probe X-ray microanalysis (EPMA) results, the reaction products of the interface are TiC, Ti₃Sn, Cu(s. s), Ag(s. s) and Cu-Sn compound. As the brazing parameters increase, the quantity of Ag(s. s) in the braze alloy and C fibers on graphite/AgCuTiSn interface reduce, while that of Cu (s. s) in the braze alloy improves. When the brazing temperature is 1093 K and holding time is 900 s, the joint can obtain the maximum room temperature shear strength 24 MPa.