Nanostructure Particle-Reinforced Transient Liquid Phase Diffusion Bonding: a Comparative Study

Abstract

Particle-reinforced aluminum-metal matrix composites (Al-MMCs) are used in many engineering applications, because they provide significant advantages when compared to monolithic aluminum alloys. However, there still exists the need to identify a suitable joining process for these materials, which minimizes particulate disruption and retains the strength of the MMC within the joint region. This study presents a comparison between joint qualities achieved when a monolithic interlayer is used vs when a nanoparticle-reinforced composite interlayer is used during transient liquid phase diffusion bonding of Al-6061 alloy containing 15 vol pct of Al 2 O 3 particles. Examination of the joint region using scanning electron microscopy (SEM), wavelength dispersive spectroscopy (WDS), and X-ray diffraction (XRD) showed the formation of eutectic phases such as Al 3 Ni, Al 9 FeNi, and Ni 3 Si within the joint zone. The results indicate that the addition of nanoparticle reinforcements into the interlayer can be used to improve joint strength and minimize particle segregation.

Spectroscopic Analyses of Nano-Dispersion Strengthened Transient Liquid Phase Bonds

“…This increase in joint shear strength was attributed to better distribution of nano-sized particles within the interlayer when smaller particle sizes are used. In both cases higher shear strengths were obtained than when pure Ni coating is used (117 MPa) [23]. The results indicate that joint strength of up to 90% that of the base metal (BM) is achievable when using a 50 nm diameter nano-sized particle-reinforced interlayer.…”

“…A high resolution SEM micrograph shown in Figure 5 revealed the presence of a nano-sized alumina particle at the center of a grain. EDX spectra of the particle showed Al and O in high concentrations with traces of Mg [23,24,33]. Comparing Gibbs free energy of formation at the bonding temperature for MgO (-1195 kJ/mol) and Al2O3 (-985 kJ/mol) it is found that Al2O3 is unstable in the presence of Mg hence it is like that some of the nano-size Al2O3 will decomposed to form MgAl2O4 compound.…”

“…When a Ni-Al2O3 coating was used as the interlayer for a bonding time of 10 minutes, shear strength of 136 MPa was recorded. However when a pure Ni coating was used under that same bonding conditions, shear strength of 117 MPa was achieved [23]. The differences in joint shear strengths obtained were attributed to the presence of a nano-sized dispersion of Al2O3 particles within the joint and the precipitation of nickel aluminide phases within the joint region.…”

“…Figure 5. (a) SEM image of nano-particle present in the center of a grain (b) EDS analysis of nano-Al2O3 particle [23] …”

Availability of in-situ reinforced active-transient liquid phase bond with good wettability for 70 vol.% SiCp/A356 composite using Al-Mg-Ga-Ti interlayer

“…In recent years, some researchers succeeded in reinforcing bond seam by externally adding ceramic particle into monolithic interlayer [24][25][26][27][28][29][30][31]. In contrast, in-situ reinforcing phase formed within the bond seam has clean interface and resultant excellent wettability with bond seam matrix [32].…”