Preparation of the high mechanical and damping performance Mg-Y-Zn alloys with three Y/Zn ratios using the hot extrusion deformation process

To develop magnesium alloys with both excellent mechanical and damping properties, three Mg–Y–Zn alloys with varying Y/Zn ratios (Mg 95 Y 3 Zn 2 , Mg 95 Y 3.5 Zn 1.5 , Mg 95 Y 3.8 Zn 1.2 (at.%)) were innovatively designed based on an arithmetic progression. Correspondingly, three different contents of the long-period stacked ordered (LPSO) phase were introduced. The alloys were prepared and deformed, followed by microstructural characterization and evaluation of mechanical and damping properties. The results show that the extruded Mg 95 Y 3.5 Zn 1.5 alloy demonstrates superior mechanical performance with UTS of 461 MPa and elongation of 10.3%. For the damping capacity, under testing conditions of ε = 0.1% and f = 1 Hz, the Q⁻ 1 value of all three as-cast alloys exceeds 0.05, while that of the three extruded alloys also exceeds 0.01. The alloy achieves a balance between damping and mechanical properties, driven by four synergistic mechanisms: dislocation dynamics, bimodal grain structure, interfacial characteristics, and intrinsic deformation of the LPSO phase. This work provides valuable guidance for the design of lightweight magnesium alloys with high properties, which are promising candidates for vibration-damping components in aerospace and transportation applications.