Abstract
In order to improve the mechanical properties of functional Mg alloys, the forming process was investigated using Mg powder mixed with Zr powder. Fine and coarse Mg and Zr powders were used and Zr content was varied from 1 mass% to 20 mass%. Milling time was 7.2 ks and the mixed powders were pressed at a temperature of 573 K and then extruded at an extrusion ratio of 30 at the same temperature. The mechanical properties of the hot-extruded alloys were examined and the effects of powder size and Zr content were discussed. In the hot-extruded Mg-Zr alloys using fine Mg and Zr powders, Zr particles were dispersed uniformly within its microstructure. It was found that the mechanical properties such as Vickers hardness, Young's modulus, bending strength and internal friction increased significantly with increasing Zr content, compared with the hot-extruded Mg material and the hot-extruded Mg-Zr alloys using coarse Mg and Zr powders. Furthermore, such mechanical properties of the hot-extruded Mg-Zr alloys using fine Mg and Zr powders were improved considerably compared with AZ31 wrought alloy, AZ91 casting alloy and the damping casting alloys such as MCM and K1A. Therefore, it was confirmed that the hot-extruded Mg-Zr alloys fabricated in this study has a potential as a structural and functional Mg alloy.
