Mechanical Properties and Corrosion Behavior of Hexagonal Boron Nitride and α-Al₂O_3w Hybrid Reinforced Laminated Cu Matrix Composites

Inspired by the hierarchical structure of pearl shells and its associated multi-scale toughening mechanism, laminated copper matrix composites reinforced with hexagonal boron nitride (HBN) and α-Al₂O₃ whiskers (Al₂O_3w) hybridization were successfully prepared by flake powder metallurgy. Results showed that with increase in HBN content, mechanical and corrosion properties of laminated composites were significantly improved. The best mechanical properties and corrosion properties were achieved at the HBN content of 1.5 wt.%. Compared with non-laminated composites, laminated composites had higher relative density, better strength, and toughness; their tensile strength and elongation were increased by 11.01 MPa and 2.57%, respectively. Fibrous α-Al₂O_3w can play a crack tip shielding effect; laminated structure of Cu matrix brings a variety of crack deflection modes and increases energy dissipation. Large aspect ratio of Cu flakes in vertical laminated direction brought about a shunting effect that made corrosion difficult to proceed to interior. This work provides new ideas for obtaining Cu matrix composites with high strength, high toughness, and good corrosion properties.