Interfacial microstructure of Al_2O_3/Ti-6Al-4V joints brazed with (Ag_(72)Cu_(28))_(97)Ti_3 filler metal

摘要

In the present work, Al_2O_3 ceramic was brazed to Ti-6Al-4V using (Ag_(72)Cu_(28))_(97)Ti_3 filler metal at 1073 - 1173 K for 1.8 ks. The interfacial phases formed and the microstructure were investigated by SEM, X-ray diffraction, and energy dispersive spectroscopy; and the mechanism of the formation of these reaction products is discussed in this paper. It has been found that the interfacial microstructure of joints brazed at 1123 K for 1.8 ks was Al_2O_3/Cu_2Ti_4O/Cu_4Ti_3O + Cu solid solution/Ag - Cu eutectic + Ag rich phase, while the interfacial structure of joints brazed at 1173 K for the same holding time was Al_2O_3/Cu_3Ti_5O + CuAl_2O_4/Cu_4Ti_3/Ag rich phase + Cu_4Ti_3.