Nanocrystalline structure and mechanical properties of vapor quenched Al-Zr-Fe alloy sheets prepared by electron-beam deposition

Nanocrystalline Al-based ternary alloys with additions of Zr and Fe have been prepared by electron-beam deposition. The composition dependence of microstructures and mechanical properties has been investigated. Fine alpha-Al grains are observed and the grain size significantly decreases with the increase of Zr content. Al-95.3-Zr-4.0-Fe-0.7 and Al-96.5-Zr-2.8-Fe-0.7 alloys consist of alpha-Al containing the coherent meta-stable L1(2) precipitate. The addition of Fe, effectively refined the grain structure, increases hardness and improves the thermal stability of the meta-stable L1(2)-Al3Zr phase. Al-95.3-Zr-4.0-Fe-0.7 alloy exhibits remarkably high tensile strength both at room temperature and above 523 K, 817 MPa at room temperature, 536 MPa at 523 K and 434 MPa at 573 K, respectively. The microstructure of Al-95.3-Zr-4.0-Fe-0.7 alloy exhibits excellent thermal stability under prolonged annealing at 523 K.