In situ (Al₃Zr_p+Al₂O_3np)/2024Al metal matrix composite with controlled reinforcement architecture fabricated by reaction hot pressing

Based on the in situ reaction between Al and ZrO₂ an (Al₃Zr_p+Al₂O_3np)/2024Al hybrid composite with a network reinforcement architecture was fabricated using reaction hot pressing. The microstructure consisting of a reinforcement-rich network surrounding the reinforcement-lean matrix resulted in unique fracture characteristics. Due to the introduction of reinforcement particles, the network structured composite exhibited an improvement in mechanical properties when compared to the unreinforced alloy. In comparison to the composite with a homogeneous distribution, the tensile strength and ductility of the network structured composite showed a 12.5 and 76.9% increase. The strengthening mechanism of the network structured composite was investigated. The reinforcement-rich network forming a three-dimensional (3D) skeleton was responsible for the enhanced strength of the composite. The large reinforcement-lean matrix interpenetrating through the network contributed to the ductility of the composite.