Preparation of low-cost, high-strength and fast-dissolving (MgO–Al3Fe)/AZ91 magnesium matrix composites using a novel in-situ reaction

Abstract

In this work, an in-situ MgO–Al3Fe particles reinforced magnesium matrix composite has been successfully prepared through a novel reaction between the AZ91 alloy and Fe3O4 precursor. The results show that the micron-sized spheroidal MgO and polygonal Al3Fe particles not only significantly refine the grains of the Mg matrix but also lead to a decrease in the number and size of β-Mg17Al12 phases. Furthermore, the in-situ MgO–Al3Fe particles have also significantly increased the volume fraction of dynamic recrystallization in the as-extruded composite. Compared to the AZ91 alloy, the strength and ductility of the as-extruded composite have been synergistically improved, with a yield strength, ultimate tensile strength, and elongation of ∼415.4 MPa, ∼480.1 MPa, and ∼5.9 %, respectively. Meanwhile, the dissolution rate of the as-extruded composite has significantly increased by about 1700 % relative to the AZ91 alloy.