In this study, 3 mol% Y2O3-stabilized zirconia (3Y-ZrO2) and commercially pure titanium (cp-Ti) joints were fabricated with an Ag68.8Cu26.7Ti4.5 interlayer (Ticusil) at 900 °C for various brazing periods. After brazing at 900 °C/0.1 h, Ti2Cu, TiCu, Ti3Cu4, and TiCu4 layers were present at the Ti/Ticusil interface, while TiCu and TiO layers were observed at the Ticusil/3Y-ZrO2 interface. In the residual interlayer, clumpy TiCu4 was formed along with the Ag solid phase. After brazing at 900 °C/1 h, Ti3Cu3O and Ti2O layers were formed at the interlayer/ZrO2 interface, while Cu2O was precipitated in the residual interlayer with Cu2O // Ag and (202)Cu2O // (202)Ag. After brazing at 900 °C/6 h, a two-phase (-Ti + Ti2Cu) region was observed on the Ti side with α-Ti // Ti2Cu and (0002)α-Ti //(013)Ti2Cu, while the TiCu layer grew at the expense of Ti3Cu4 and TiCu4. The bonding mechanisms and diffusion paths were explored with the aid of Ag-Cu-Ti and Ti-Cu-O ternary phase diagrams.