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

Abstract

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 c-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 c.

Bonding SiCp/Al Composites via Laser-Induced Exothermic Reactions

“…The interlayer products were a mixture of three phases. According to the phase diagram and previous studies [33,34], the dark phase (point F) was confirmed to be the NiAl phase. The gray reticular phase (point G) and white small block phase (point H) were supposed to be the Ni 3 Al 5 Zr 2 and Ni 2 AlZr, respectively.…”

Research Progress of Ceramic and Metal Welding Technology

“…Self-propagation high-temperature synthesis(SHS)was proposed by Soviet scientist Merzhanov et al in 1967 [35]. Its principle is to induce internal chemical reaction by applying external energy to the material, and the heat released by the reaction promotes it to continue, so as to synthesize new materials [36][37].…”