Synergistic enhancement of strength and ductility in 2024Al composites via hybrid addition of (TiZrHfTa)C4 high‑entropy carbide and AlCoCrFeNi high‑entropy alloy particles

In this work, a novel hybrid 2024Al composite reinforced with (TiZrHfTa)C high‑entropy ceramic (HEC) particles and AlCoCrFeNi high‑entropy alloy (HEA) particles was successfully fabricated by spark plasma sintering. The results show that the single HEC/2024Al composite exhibits a strength–ductility trade‑off: increasing the HEC content from 5 vol% to 25 vol% raises the yield strength from 279.5 MPa to 461.8 MPa, but drastically reduces the plastic strain from 25.8% to 3.42%. In contrast, the hybrid composite containing 20 vol% HEC and 5 vol% HEA simultaneously improves both properties, achieving a yield strength of 489.0 MPa (a 5.9% increase) and a plastic strain of 10.12% (a 197% increase) compared to the 25 vol% HEC/2024Al composite. Microstructural characterization reveals the uniform distribution of reinforcements and the formation of a core-shell interfacial structure between the HEA particles and the aluminum matrix, which promotes strong interfacial bonding. Mechanical testing demonstrates that the synergistic effect of the dual HEC-HEA reinforcements significantly enhances the strength of composite while maintaining a useful level of ductility. This work provides a new strategy for designing high-performance AMCs with balanced mechanical properties through the hybrid use of high-entropy ceramic and alloy reinforcements.