Microstructure, mechanical properties and damping capacity of as-extruded Mg-1.5Gd alloys containing rare-earth textures

In this work, a novel high damping Mg-1.5Gd binary alloy with ultrahigh ductility and adequate strength was prepared by hot extrusion at different temperatures of 360 °C, 420 °C and 480 °C. The microstructure, damping capacity and mechanical properties of the as-extruded alloys were systematically investigated. The results showed that the tensile elongation of all as-extruded Mg-1.5Gd alloys is over 40%, which is mainly ascribed to the formation of the <21-1-1> rare-earth (RE) texture component in alloys after hot extrusion, and the highest damping value Q−1 is 0.086 at ε = 10−3. In addition, the relationship between the strain amplitude and damping value Q−1 fit the Granato-Lücke (G-L) dislocation theory for the alloys well. The damping capacity of the alloys was discussed in detail in terms of the dislocation motion and G-L plot. Under the same comparison conditions, the damping value Q−1 and yield strength of the Mg-1.5Gd alloy extruded at 360 °C were higher than those of Mg-1Y and comparable with those of Mg-0.6Zr considered to be a typical high damping alloy. This implied that dilute wrought Mg-Gd binary alloys containing RE textures exhibited promising potential for developing high-performance damping alloys in terms of both damping capacity and yield strength.