Towards the strength-ductility synergy of Al2O3/Al composite through the design of roughened interface

Abstract

In the study, a roughened interface is designed to achieve the strength-ductility synergy of Al2O3/Al composites fabricated by flake powder metallurgy. The roughened SiO2@Al2O3 platelets are fabricated by high-shear dispersion process and subsequent sintering at the high temperature. The results show that different morphologies of asperities on the surface of SiO2@Al2O3 platelets can be obtained via controlling the sintering time. As the roughness increases, the strength and ductility of SiO2@Al2O3/Al composites are simultaneously improved. Load transfer efficiency is enhanced by platelet-matrix interlocking at the roughened SiO2@Al2O3/Al interface, compared to Al2O3/Al composite with smooth Al2O3–Al interface. The improved tensile ductility in SiO2@Al2O3/Al composite is attributed to the extrinsic toughening mechanism. This design strategy offers a simple and promising approach to improve the mechanical properties of metal matrix composites.