Based on cost-effective wrought Mg-Bi based alloy with high strength and ductility, this study investigates the damping properties of Mg-xBi (x: 3, 6, 9 wt.%) binary alloys at both ambient and elevated temperatures. The results reveal that as-extruded Mg-6Bi and Mg-9Bi alloys not only maintain adequate strength but also exhibit superior damping performance at room temperature compared to alloys with similar strength. The damping behavior of Mg-xBi binary alloys aligns with the Granat-Lücke dislocation pinning model, and their damping performance improves with increasing strain (ε). In comparison to as-extruded pure Mg, the addition of Bi significantly enhances high-temperature damping properties. The high-temperature damping behavior of Mg-xBi binary alloys is consistent with the viscoelastic relaxation mechanism, with damping performance decreases as vibration frequency (f) increases. Notably, when f exceed 5 Hz, the influence of frequency on damping performance becomes negligible. The P1 peak observed in the damping curves of Mg-xBi binary alloys demonstrates distinct thermal activation characteristics. The activation energies for the P1 peak in as-extruded pure Mg and Mg-xBi alloys are 128.1 kJ/mol, 133.5 kJ/mol, 134.1 kJ/mol, and 138.3 kJ/mol, respectively.
- Article type
- Year
- Co-author
Open Access
Full Length Article
Issue
Open Access
Full Length Article
Issue
This study investigates the influence of varying rolling reduction on the evolution of microstructure and mechanical properties of Mg10Gd (in wt%) alloys by caliber rolling (CR). By increasing the rolling reduction from 45 % to 65 %, a uniform bimodal structure is obtained in which coarse grains (CGs) larger than 10 µm are surrounded by fine grains (FGs). The MgGd alloy subjected to 65 % reduction exhibits superior mechanical properties, i.e. yield strength (YS) of ~424 MPa, ultimate tensile strength (UTS) of ~500 MPa and elongation (El.) of ~3.3 %. The synergistic improvement in strength and ductility is primarily attributed to the combined effects of low-angle grain boundary (LAGB) strengthening, precipitation strengthening, and the coordinated deformation exhibited by the bimodal structure. In addition, caliber rolling also provides a novel approach for the design of Mg alloys with uniform bimodal structures that exhibit both high strength and ductility.
京公网安备11010802044758号