Loss-free tensile ductility of aluminum composites through in situ reaction and interfacial modification

The strength-ductility trade-off is usually an unavoidable situation in metal matrix composites. In present study, in-situ nano-Al 2 O 3 and Al 2 Cu hybrid reinforced Al Si matrixed composite was prepared by powder metallurgy. Through in-situ synthesis and interface modification, the composite achieved a good balance of strength and ductility. The tensile strength of the composites is 511.67 MPa, marking a remarkable 112 % increase compared to the matrix, while maintaining virtually no loss of plasticity. The experimental results demonstrate that the primary enhancing factors for the strength of the composites are the thermal mismatch strengthening and Orowan strengthening mechanisms, which are a result of precipitation of in-situ nano-Al 2 Cu phase and nano-Al 2 O 3 particles. The enhanced plasticity of the material is attributed to the formation of an Al/Al 2 O 3 /Si sandwich interface, which exhibits a lower mismatch compared to Al Si interface. This improvement enhances the load transfer capacity between matrix and Si particles, leading to a substantial increase in yield strength while minimizing loss of plasticity. The current study aims to overcome strength-ductility trade-off in metal matrix composites, which can provide new insights for production of high-performance metal matrix composites.