Microstructure and formation mechanism of SHS joining between C_f/Al composites and TiAl intermetallic with Al–Ni–CuO interlayer

In this study, it was reported a novel approach for joining C_f/Al composites and TiAl intermetallic by self-propagating high-temperature synthesis (SHS). Mixed powders of 14Al–2Ni–3CuO were used as the SHS interlayer, and differential thermal analysis test of Al–Ni–CuO interlayer was conducted to analyze the exothermic characteristic. Sound joint was got by SHS joining under the conditions of 600 °C, 30 min, and 5 MPa. The joint was characterized by scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), and X-ray diffraction (XRD). TiAl₃ and NiAl₃ are, respectively, formed in the TiAl/interlayer and C_f/Al/interlayer interfaces. Reaction products of Ni₂Al₃, NiAl₃, Al₂O₃, and Cu were observed in the interlayer. And the formation mechanism of SHS joining was investigated.