Microstructure, mechanical properties and damping behavior of novel Mg-Ga-Zn alloys fabricated by medium-high strain rate rolling

Abstract

This study examines the grain characteristics, dynamic precipitation phase characteristics, and texture evolution of Mg-Ga-xZn alloys produced through medium-high strain rate rolling. It investigates the impact of Zn on the mechanical and damping properties of Mg-Ga sheet. The addition of Zn reduces the solid solubility of Ga in α-Mg, facilitating dynamic precipitation, grain refinement, and weakening of the basal texture of the sheet, ultimately enhancing strength and damping performance. The yield strength of the sheet initially increases and then decreases with increasing Zn content. The Mg-5Ga-0.6 Zn alloy demonstrates the best overall mechanical properties, with a yield strength, tensile strength, and elongation of 221 MPa, 304 MPa, and 28.6%, respectively, primarily attributed to fine-grained strengthening. Damping performance at low strain amplitudes also follows a similar trend with increasing Zn content, with Mg-5Ga-0.6 Zn showing the highest damping values. The study suggests that the decrease in damping performance due to Zn can be linked to the reduced solid solubility of Ga in α-Mg. Specifically, at a strain amplitude of 1 × 10^–3, the damping values Q^-1 of Mg-5Ga, Mg-5Ga-0.6 Zn, and Mg-5Ga-1.2 Zn alloy sheets are 0.0167, 0.0152, and 0.0174, respectively. These findings have implications for the development of bio-implantable magnesium alloys with high damping properties.