Bonding SiCp/Al Composites via Laser-Induced Exothermic Reactions

Abstract

In this paper, the SiCp/Al composites were bonded via laser-induced exothermic reactions of a Ni–Al–Zr interlayer. The Ni–Al–Zr interlayer was designed based on its exothermic property and chemical compatibility with the SiCp/Al composites. The influences of the interlayer composition and bonding pressure on the joint microstructure and shear strength were investigated. Results indicated that high exothermic reactions occurred in the Ni–Al–Zr interlayer and realized the reliable bonding with the SiCp/Al composites. The interlayer products were the eutectic structure of NiAl+Ni2AlZr+Ni3Al5Zr2. NiAl3 and Ni2Al3 reaction layers were formed at the bonding interfaces. The interlayer composition and the bonding pressure determined the morphology and distribution of the voids and the reaction layers, thus controlling the joint shear strength. When the SiCp/Al composites were bonded using the interlayer with the Zr content of 15 wt.% under the bonding pressure of 3 MPa, the joint shear strength reached the maximum of 24 MPa.