Insight into the precipitation behavior and mechanical properties of Sc-Zr micro-alloying TiB 2 /Al-4.5Cu composites

The strength-ductility synergy and high-temperature stability of the particle-reinforced aluminum matrix composites have been a tough challenge. Here we present a strategy of Sc-Zr micro-alloying to advance this issue through an optimized salt-metal reaction process and multi-stage heat treatment. The developed Sc-Zr micro-alloying TiB 2 /Al-4.5Cu composites exhibit a remarkable combination of tensile strength and ductility even at 573 K (The ultimate tensile strength is 247 ± 8.34 MPa while the uniform elongation is 8.19 ± 2.53%). We have emphasized our insight into the precipitation behavior and mechanical properties of the composites at various temperatures to expand a better understanding of the failure mechanisms. Our findings are both fundamental and practical significance for further advancing the high-temperature performance of aluminum matrix composites.