In-Situ Al ₂O ₃-Al Interface Contribution Towards the Strength-Ductility Synergy of Al-CuO Composite Fabricated by Solid-State Reactive Sintering

Abstract

Probing the interface is of great importance for tailoring the mechanical performance of Al matrix composites (AMCs) to achieve strength-ductility synergy. This work contributes an in-depth understanding of the in-situ Al₂O₃-Al interfaces integrating the "Al₂O₃-intermixing region-Al" interface structure and interfacial segregation/precipitation in Al-7 wt.% CuO (Al-7CuO) composite fabricated by solid-state reactive sintering. It was elucidated that the "Al₂O₃-Al intermixing region" would enhance the cohesion and plastic stability of the Al₂O₃-Al interface. Meanwhile, Cu segregation and CuAl₂ precipitation turn to suppress dislocation nucleation/movement and increase the interfacial slippage resistance of the Al₂O₃-Al interface. Further characterization of the fracture morphology suggests that the robust in-situ Al₂O₃-Al interface exerts prominent contribution to the remarkable mechanical properties of Al-7CuO composite through effective load-transfer and changed crack propagation path.

Keywords: Al-CuO composite, In-situ Al2O3-Al interface, Al2O3-Al intermixing, Interfacial segregation/precipitation, Mechanical property