Optimization of ZK60 magnesium alloy properties via secondary extrusion of rapidly solidified strips

Abstract

The microstructure and mechanical properties of ZK60 extruded alloy by rapid solidification (RS) and as-cast ingot processes were investigated using optical microscope, scanning electron microscope, X-ray diffraction, electron back-scatter diffraction, and mechanical tests. The results show that the RS ZK60 extruded alloy exhibits relatively high tensile yield strength (TYS), compressive yield strength (CYS) and elongation of 300.8 MPa, 303.6 MPa and 18.6%, respectively. The RS ZK60 extruded alloy with an ultra-fine grain size of 1.28 μm not only has a weak texture with a maximum polar density of 3.3 but also addresses the tension−compression asymmetry with a CYS/TYS ratio of approximately 1.0. The calculation of the strengthening mechanism indicates that the improvement in the mechanical properties of the RS ZK60 extruded alloy is primarily attributed to grain refinement.