Microstructure and mechanical properties of SiCp/CF/Al hybrid composites with heterostructure constructed by macroscopic “core-shell” structure

Abstract

Designing heterostructure is an effective way to comprehensively improve the strength-ductility of composites. However, the current methods of heterostructure integration consumes a large amount of energy. In this study, a macroscopic “core-shell” structure is designed with low cost and low energy consumption. The SiC particles (SiCp) and carbon fiber (CF) reinforced aluminum-based hybrid composite (SiCp/CF/Al) with heterostructure was fabricated utilizing the spark plasma sintering (SPS) method. The microstructure, interfacial structure, and mechanical properties of the SiCp/CF/Al before and after hot rolling were comprehensively investigated. The results revealed that the Vickers hardness values of the rich particle zone with high SiCp content were 54.32% and 48.10% higher than those of the poor particle zone before and after hot rolling, respectively. The synergistic strengthening effect of SiCp and CF significantly enhanced the yield strength and plasticity of the SiCp/CF/Al. Before and after hot rolling, the yield strength of SiCp/CF/Al was 242.68% and 173.16% of single CF-reinforced Al matrix composites, respectively. The extrinsic toughening was achieved through crack passivation and deflection at the interface of the rich particle zone and poor particle zone. Furthermore, the hindering and storing effects of the SiCp and CF on dislocations represented the primary intrinsic toughening mechanisms.