Achieving dual direct interfacial bonding in AlN and SiCp/Al joints enabled by Mg-induced synchronous deoxidation

A novel low-temperature bonding strategy employing an Al-Si-Mg interlayer was developed to join AlN ceramics to SiCp/Al composites. Through a dual deoxidation mechanism, Mg simultaneously removed the surface oxides (AlN_xO_y and SiO₂) on both ceramics, enabling direct interfacial bonding between the Al matrix and AlN/SiC. The joints achieved a maximum shear strength of 83.8 MPa (580 °C/30 min) and a peak thermal diffusivity of 75.6 mm²/s (580 °C/15 min). Microstructural analysis identified the seam consisting of (Al,Cu)ss, Al₄Cu₂Mg₈Si₇, Al₂Cu, and interfacial reaction compounds. Geometric phase analysis (GPA) further revealed that residual stress localized as nano-scale strain concentration at brittle interphases, directly linking microstructural evolution to mechanical performance. This approach provides a reliable method for manufacturing high-performance, thermally conductive AlN/SiCp/Al hybrid structures in electronic packaging.