Interfacial microstructure and joining properties of TiAl/Ti3AlC2 diffusion bonded joints using Zr and Ni foils as interlayer

•TiAl intermetallics and Ti3AlC2 ceramics were diffusion bonded in a vacuum.•The general interfacial microstructure of the joint was clarified.•The bonding temperature has a significant effect on the diffusion and reaction of Ni with other elements.•The maximum shear strength reached 103.6 MPa accompanied by a brittle intergranular and transgranular fracture.

Diffusion bonding of TiAl intermetallic to Ti3AlC2 ceramic was carried out using Zr and Ni foils as interlayer. The interfacial microstructure and joining properties were characterized by electronic microscopy investigation and shear strength test, respectively. The microstructure observations revealed that the general interfacial microstructure of the joint bonded at 850 °C was consisted of γ-TiAl + τ3-Al3NiTi2, τ3-Al3NiTi2, τ4-AlNi2Ti, τ4-AlNi2Ti + Ni10Zr7, Ni7Zr2, Ni5Zr, Ni, Ni3(Al,Ti), Ni3(Al,Ti) + Ti3AlC2 from TiAl to Ti3AlC2. The bonding temperature had a great influence on the diffusion and reaction of Ni with other elements, generating different interfacial morphology of joints. The shear test results showed that the maximum shear strength reached 103.6 MPa. Fracture occurred along the ceramic substrate adjacent to the bonding interface, showing a brittle intergranular and transgranular fracture mode.