Behaviors of interfacial elements during the brazing of SiO₂ glass ceramic to Ti-6A1-4V with AgCu/Ni interlayer

AgCu/Ni composite interlayer was used to join SiO₂ glass ceramic to Ti-6Al-AV alloy successfully,obtaining the largest joint shear strength 110 MPa.Ag,Cu and Ni in the interlayer and Ti in the Ti-6Al-4V alloy affect the joint formation and interfacial products significantly.To understand the joint formation process better,behaviors of elements Ag,Cu,Ni and Ti during the brazing of SiO₂ glass ceramic to Ti-6Al-4V alloy were investigated in the present work.Active element Ti is the most important component in the joining,realizing the metallurgical bonding of SiO₂ glass ceramic to braze alloy.Cu together with Ni reacts to Ti in the base material by Ti-Cu-Ni ternary eutectic reaction,which is beneficial for reducing the massive TiCu and/or Ti-Ni brittle intermetallic compounds on the joint interface.Dispersion of Ag decreases the brittleness of the whole joint effectively.