Investigation on diffusion bonding of TiAl intermetallic to Ti₃AlC₂ ceramic with Ni interlayer

In this study, diffusion bonding of TiAl alloy and Ti₃AlC₂ ceramic was carried out using Ni foil as interlayer in a vacuum atmosphere. The interfacial microstructures and the mechanical properties of the diffusion bonded joints were evaluated. Result showed that the interfacial microstructure of the joint from TiAl to Ti₃AlC₂ side could be divided into Al₃NiTi₂, AlNi₂Ti, Ni₃(Al,Ti), Ni, Ni₃(Al,Ti), Ni(Al,Ti), Ni₃Al+TiC_x+Ti₃AlC₂, respectively. The shear strength test showed that an average value of 45.9 MPa was achieved. The crack propagated along the interface between TiAl intermetallic and Ni interlayer during the shear test. The mechanisms for formation of those compound layers during bonding process and the determinant of the fracture location were also discussed.