Properties of Layered Cu-Based Composites Prepared by Spark Plasma Sintering

Bulk lamellar-structured Cu70Zr15Ti15@Cu composites were successfully fabricated via spark plasma sintering (SPS) of flake-like Cu70Zr15Ti15@Cu amorphous composite powders. These core-shell powders were synthesized by performing electroless copper plating on ball-milled flake-like Cu70Zr15Ti15 amorphous precursor powders. The systematic influence of sintering temperature on the microstructure evolution, hardness, surface wettability, and corrosion resistance of the consolidated composites was thoroughly investigated. The results demonstrate that the phase constitution of the Cu70Zr15Ti15 powders undergoes a distinct transformation: the initial Cu51Zr14 single phase transforms into Cu51Zr14 + amorphous dual-phase mixture after ball milling. The average crystallite size of the Cu matrix increases exponentially with the elevation of sintering temperature. Both the bulk density and Vickers hardness of the composites show a near-linear increasing trend as the sintering temperature rises. Meanwhile, the characteristic lamellar microstructure of the material evolves from a coarse thick-layered morphology to a refined fine–lamellar architecture with increasing sintering temperature. The electrochemical corrosion resistance of the composites in 3.5 wt% NaCl solution is progressively enhanced at higher sintering temperatures. Notably, the surface wettability of both the mechanically polished and electrochemically corroded samples exhibits a clear transition from hydrophilicity to hydrophobicity as the sintering temperature increases. Furthermore, the underlying mechanisms governing the corrosion behavior evolution and surface wettability transition are systematically elucidated.