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Ductility and electrical conductivity of metallic materials are inversely correlated with their strength,resulting in a difficulty of optimizing all three simultaneously. We design an Al-Sc-Zr-based alloy using semisolid extrusion to yield a good trade-off between strength and ductility along with excellent electrical conductivity. The Al-0.35Sc-0.2Zr wire with a diameter of 3 mm exhibited the best combined properties: a tensile strength of 210 ± 2 MPa, elongation of 7.6% ± 0.5%, and an electrical conductivity of 34.9 ± 0.05 MS/m. The average particle size of nanosized Al_3(Sc, Zr) precipitates increased from 6.5 ± 0.5 nm to 25.0 ± 0.5 nm as the aging time increased from 1 h to 96 h at 380 °C, accompanied by the corresponding volume fraction variation from(6.2 ± 0.1) × 10~(-4) to(3.7 ± 0.1) × 10~(-3). As proved by transmission electron microscopy observation, the high strength originates from the effective blockage of dislocation motion by numerous nanosized Al_3(Sc, Zr) precipitates whilst both electrical conductivity and ductility remain at a high level due to the coherent precipitates possessing an extremely low electrical resistivity.
Ductility and electrical conductivity of metallic materials are inversely correlated with their strength, resulting in a difficulty of optimizing all three simultaneously. We design an Al-Sc-Zr-based alloy using semisolid extrusion to yield a good trade-off between strength and ductility along with excellent electrical conductivity. The Al-0.35Sc-0.2Z wire with a diameter of 3 mm exhibited the best combined properties: a tensile strength of 210 ± 2 MPa, elongation of 7.6% ± 0.5%, and an electrical conductivity of 34.9 ± 0.05 MS / m. The average particle size of nanosized Al 3 (Sc, Zr) precipitates increased from 6.5 ± 0.5 nm to 25.0 ± 0.5 nm as the aging time increased from 1 h to 96 h at 380 ° C, accompanied by the corresponding volume The fraction variation from (6.2 ± 0.1) × 10 ~ (-4) to (3.7 ± 0.1) × 10 ~ (-3). As proved by transmission electron microscopy observation, the high strength originates from the effective blockage of dislocation motion by numerous nanosized Al_3 (Sc, Zr) prec ipitates whilst both electrical conductivity and ductility remain at a high level due to the coherent precipitates possessing an extremely low electrical resistivity.