Mg-9.5Gd-4Y-2Zn-0.3Zr alloy wires with a diameter of 1.2 mm were fabricated by a multistage drawing process with a cumulative area reduction (CAR) of 96% at 500 °C using as-extruded rods with a diameter of 6 mm as the raw material. Investigated the impact of microstructural transformations on the mechanical performance of these wires, with a focus on phase evolution, texture changes, and grain refinement. In the alloy, second-phase 18R-LPSO, rare-earth-rich (RE-rich) phase, and ZnZr distributed at the grain boundaries along the extrusion direction (ED) or the drawing direction (DD), which were different from the intragranular 14H-LPSO phase, were observed. Significantly, we observed the transformation of blocky 18R-LPSO phases into sub-2μm W-MgZnRE particles during hot drawing. All the as-extruded and as-drawn wires exhibited equiaxed grains with average sizes between 4 μm and 7 μm. The as-extruded wires exhibited a texture with {0001} perpendicular to ED. As the CAR increased, the texture of the wires transformed into a basal texture with {0001} parallel to DD. The ultimate tensile strength (UTS) and tensile yield strength (TYS), respectively, increased from 369 MPa to 283 MPa for the as-extruded wire to 466 MPa and 436 MPa for the as-drawn wire with CAR increasing to 55%, and then decreased to 328 MPa and 318 MPa for the wire with CAR increasing to 96%. The elongation (EL) reduced from 8.01% to 1.37% with CAR increasing to 96%. As CAR exceeded 55%, the increased volume fraction of the W-MgZnRE phase resulted in a significant decrease in both the strength and the plasticity of the wires. The evolution of microstructure and mechanical properties provides possibility for regulating both the strength and elongation of the Mg-Gd-Y-Zn-Zr alloy wires by optimizing the drawing process.

中文翻译：

---

热拉制 Mg-9.5Gd-4Y-2Zn-0.3Zr 合金丝的相变、织构演变和力学性能

使用直径为 1.2 mm 的挤压棒材，通过多级拉拔工艺制造了直径为 1.2 mm 的 Mg-9.5Gd-4Y-2Zn-0.3Zr 合金丝，在 500 °C 下累积断面收缩率 (CAR) 为 96%。 6毫米为原料。研究了微观结构转变对这些线材机械性能的影响，重点是相演化、织构变化和晶粒细化。合金中，第二相18R-LPSO、富稀土（RE-rich）相和ZnZr沿挤压方向（ED）或拉拔方向（DD）分布在晶界处，与合金中不同。观察到颗粒内14H-LPSO相。值得注意的是，我们观察到热拉过程中块状 18R-LPSO 相转变为亚 2μm W-MgZnRE 颗粒。所有挤压和拉拔线材均呈现出平均尺寸在 4 μm 至 7 μm 之间的等轴晶粒。挤出时的线材呈现出与 ED 垂直的 {0001} 纹理。随着 CAR 的增加，线的纹理转变为具有与 DD 平行的 {0001} 的基础纹理。随着 CAR 增加到 55%，极限拉伸强度 (UTS) 和拉伸屈服强度 (TYS) 分别从挤压线材的 369 MPa 增加到 283 MPa，拉拔线材的极限拉伸强度 (UTS) 和拉伸屈服强度 (TYS) 分别增加到 466 MPa 和 436 MPa，并且然后线材的压力降低至 328 MPa 和 318 MPa，CAR 增加至 96%。伸长率 (EL) 从 8.01% 降低至 1.37%，而 CAR 增加至 96%。当CAR超过55%时，W-MgZnRE相体积分数的增加导致线材的强度和塑性显着下降。微观结构和力学性能的演变为通过优化拉丝工艺调节Mg-Gd-Y-Zn-Zr合金丝的强度和伸长率提供了可能性。