# High Performance Mg Alloy with Designed Microstructure and Phases

## TL;DR

This paper introduces a new magnesium alloy with a special microstructure that combines high strength and ductility.

## Contribution

The novelty lies in designing a Mg-Gd-Y-Zn-Zr alloy with a bimodal microstructure and specific phases to achieve superior mechanical properties.

## Key findings

- The alloy exhibits a high strength-ductility synergy due to grain refinement and specific phase distribution.
- Strain transfer between different regions promotes uniform deformation and improves ductility.

## Abstract

A high strength and ductile Mg-Gd-Y-Zn-Zr alloy was designed and fabricated. The local strain evolution of the alloys during plastic deformation was analyzed using high-resolution digital image correlation (DIC). The results showed that the β particles, nano-sized γ’ phases, and LPSO phases were distributed in the as-extruded alloy and a bimodal microstructure was exhibited, including elongated un-dynamic recrystallized grains and fine dynamic recrystallized grains. With increasing extrusion ratio, the grain size remained, with the volume fraction of dynamic recrystallization of the as-extruded alloy increasing from 30% to 75%, and the as-extruded alloy exhibited a high strength-ductility synergy, which is attributed to the grain refinement, extensive β particles, and elongated block-shaped LPSO phases. The strain evolution analysis showed that a strain-transfer from un-DRXed regions to adjacent DRXed regions and LPSO phases can promote uniform plastic deformation, which tends to improve the ductility of the alloy.