Joining of C_f/Al composites and TiAl intermetallics by laser-induced self-propagating high-temperature synthesis using the Ni-Al-Zr interlayer

To extend the materials application and achieve composite structures with combined advantages, the C_f/Al composites were joined with TiAl intermetallics by a novel laser-induced self-propagating high-temperature synthesis joining method. In this study, a Ni-Al-Zr interlayer was designed based on the calculation of the adiabatic temperature. The joint microstructure was characterized using scanning electron microscopy (SEM), energy dispersive spectrometry (EDS), transmission electron microscope (TEM) and X-ray diffraction (XRD). The results showed that the NiAl + Ni₂AlZr + Ni₃Al₅Zr₂ eutectic were produced during the joining. The Al₃NiTi₂, Ni₂Al₃ and NiAl₃ reaction layers formed respectively on both sides. A nanoscale thin Zr-C reaction layer formed on the NiAl₃/C_f interface and greatly enhanced the bonding quality on the C_f/Al side. The effect of the interlayer composition and joining pressure on the joint microstructure and mechanical property was investigated. The highest joint shear strength was 68.71 MPa at a pressure of 4 MPa when the Zr content was 5 wt.%.