Effect of Zirconium additions on microstructure and mechanical properties of hot rolled Al-Mg alloys

Abstract

In this study, the mechanical properties and microstructure of as cast and hot rolled Al-4 Mg alloy matrix was carried out and the effect of Zirconium additions onAl-Mg alloys were also investigated. X-ray powder diffraction was performed for studying the crystalline nature of Al-4 Mg alloy and Al-4 Mg-0.2Zr alloy. Tensile specimens were prepared from hot rolled plates as per ASTM standards and tensile test were conducted at room temperature. Addition of Zr to the alloy matrix showed a reduction in grain size from 117 ± 8 µm to 73 ± 23 µm that can be attributed to formation of Al3Zr dispersoids. Results showed an increase in ultimate tensile strength from 244 MPa to 254 MPa after addition of Zr to Al-Mg alloy. This increase in strength can be attributed to grain refinement due to formation of Al3Mg2 dispersoids. Fractography results displayed loss of ductility with the formation of Al3Zr phase. The increase in strength and reduction in elongation due to Zr addition in Al-Mg alloy makes it suitable for aerospace application.