A novel Ag₇₂Cu₂₈-modified high-volume-fraction SiC_P/Al composite with superior mechanical and thermal properties

High-volume-fraction SiC_P/Al composites show great promise for electronic packaging applications, but poor interfacial bonding and non-uniform microstructure limit their performance enhancement. This study fabricated a series of high-volume-fraction SiC_P/Al composites containing 5–15 wt% Ag₇₂Cu₂₈ eutectic brazing filler via spark plasma sintering. It systematically analyzed the effects of Ag₇₂Cu₂₈ addition on the microstructure and properties of the composites. Microstructural analysis reveals a unique dual modification mechanism: Ag segregates to the SiC/Al interface, reducing the oxide layer thickness from 2 to 3 nm to 1–2 nm and significantly improving interfacial metallurgical bonding; meanwhile, phase separation of Ag-Cu in the matrix produces Ag-rich Al(Ag) solid solution and Cu-rich Al₂Cu precursors, forming a strengthening network. The chain-like network provides both a reinforcement framework and thermal-conduction pathways while avoiding excessive networking-induced defect accumulation. The composite achieved optimal properties at 10 wt% Ag-Cu: 99.1 % relative density, 298.5 HV Vickers hardness (50 % increase over baseline composite), 282.7 MPa flexural strength (87% increase), and 128.42 W/(m·K) thermal conductivity. This study provides a novel strategy for developing high-performance electronic packaging materials.