Microstructure evolution and formation mechanism of laser-ignited SHS joining between Cf/Al composites and TiAl alloys with Ni-Al-Ti interlayer

摘要

In this study, C_f/Al composites and TiAl alloys were joined by a new method named laser-ignited selfpropagating synthesis(SHS). Mixed powders of 63.0Ni-31.9Al-5.1Ti(wt%) were used as joining interlayer.Perfect joint was got. The microstructure evolution and formation mechanism of the SHS joint were investigated by scanning electron microscopy(SEM), energy-dispersive spectroscopy(EDS) and X-ray diffraction(XRD). Results show that localized melting occurs on both sides. One γ-Ni_(0.35)Al_(0.30)Ti_(0.35) and two Ni-Al reaction layers form,respectively, in the TiAl/interlayer and C_f/Al/interlayer interfaces. The combustion of Ni-Al-Ti interlayer begins with the sharp reaction of Ni and Al. The interlayer product is a eutectic organization of NiAl and Al-rich γ.