Synergistic improvement of damping capacity and mechanical properties of magnesium alloy prepared with UHP technology

The contradictory relationship between the damping capacity and strength of metals, governed by dislocation mechanisms, poses a challenge in improving simultaneously through dislocation strengthening. Accordingly, exploring novel methods to synergistically enhance mechanical properties and damping capacity is designated as a focal research subject in recent years. The study at hand aims to tackle this challenge through the manipulation of microstructures in Mg-Y-Er-Zn-Zr alloy via ultra-high pressure (UHP) heat treatment, yielding Mg-based alloys of exceptionally lightweight with outstanding damping and mechanical characteristics. After UHP, a significant refinement in the alloy's grain size is observed, with the average grain size decreasing from 114 to 23 μm, accompanied by substantial introduction of dislocations into the matrix, along with the emergence of twin within the matrix. The tensile strength of M-6GPa-1000 alloy subjected to UHP treatment achieves 326 MPa, demonstrating a 95% increase compared to ordinary heat treatment alloys while maintaining an elongation of 11.9%. Additionally, the damping capacity value Q⁻¹ of M-6GPa-1000 alloy treated with UHP during the low-strain zone is 0.03, exhibiting a threefold increase compared to that of the conventionally heat-treated alloy. Through UHP treatment, the alloy's microstructure is regulated, achieving a synergistic enhancement of strength and damping capacity. The study comprehensively analyzes the synergistic improvement of mechanical and damping characteristics in the alloy. The proposed UHP technology holds significant potential for the fabrication of advanced Mg-Re components.