Scholarlink

<p>The enhancement of mechanical properties in magnesium (Mg) alloys through the pre-setting of tensile twins (TTs) has been widely demonstrated. Nevertheless, the impact of the initial microstructure, particularly the initial distribution of grain size and orientation, on the microstructure and mechanical characteristics of pre-twinned Mg sheets demands further elucidation.&#xa0;Therefore, in this study, the corrugated wide limit alignment (CWLA) method was used to induce TTs at 200&#xa0;°C in Mg sheets with different initial microstructures, which are named as-received-A (AR-A) with a strong basal texture and uniform equiaxial grains and as-received-B (AR-B) with a fiber texture and heterogeneous grains, respectively. The corresponding sheets after CWLA are named C200-A and C200-B, respectively. The experimental results indicate that both C200-A and C200-B developed a transverse direction (TD)-tilted texture, and the newly generated TD-tilted texture component significantly weakens the basal texture and refines the grains. In comparison with C200-B, the texture intensity of C200-A exhibited a more pronounced reduction, reaching 36 pct. This can be attributed to the fact that AR-A, characterized by fine equiaxed grains and a strong basal texture, is more conducive to the activation of TTs. The mechanical properties of C200-A were synergistically improved, with a 27 pct increase in ultimate tensile strength (UTS), a 50 pct increase in yielding strength (YS), and a 21 pct increase in elongation, and the homogeneous plastic deformation stage is increased significantly. The reason is the significant activation of basal &lt; a &gt; slip and the synergistic effect of multiple dynamic recrystallization (DRX) mechanisms to refine grain size by 41 pct. The elongation of C200-B decreased by 20 pct. The main reason is related to the DRX mechanism. The grain refinement of the coarse grain region mainly via continuous dynamic recrystallization (CDRX) and the accompanied abnormal grain growth of the fine grain region, causing grain homogenization. High plasticity due to the AR-B heterogeneous structure then disappears. Therefore, it is suggested that Mg sheets with fine equiaxed grains and strong basal texture is more readily accessible to obtain good comprehensive mechanical properties via pre-setting TTs.</p>

错误：搜索内容不能为空，请输入英文关键词
错误：关键词超出字数限制，请精简
高级检索

Effect of Initial Microstructure on Twinning, Dynamic Recrystallization Behaviors, and Mechanical Properties of Pre-twinned AZ31 Mg Sheets

  • 期刊论文

  • 发表日期：

    2025年1月22日

查看全文
  • Zhijian Li,
  • Huihui Nie,
  • Hongyang Zhang,
  • Shaoxin Yang,
  • Liuwei Zheng,
  • Hongsheng Chen,
  • Wei Liang

摘要

The enhancement of mechanical properties in magnesium (Mg) alloys through the pre-setting of tensile twins (TTs) has been widely demonstrated. Nevertheless, the impact of the initial microstructure, particularly the initial distribution of grain size and orientation, on the microstructure and mechanical characteristics of pre-twinned Mg sheets demands further elucidation. Therefore, in this study, the corrugated wide limit alignment (CWLA) method was used to induce TTs at 200 °C in Mg sheets with different initial microstructures, which are named as-received-A (AR-A) with a strong basal texture and uniform equiaxial grains and as-received-B (AR-B) with a fiber texture and heterogeneous grains, respectively. The corresponding sheets after CWLA are named C200-A and C200-B, respectively. The experimental results indicate that both C200-A and C200-B developed a transverse direction (TD)-tilted texture, and the newly generated TD-tilted texture component significantly weakens the basal texture and refines the grains. In comparison with C200-B, the texture intensity of C200-A exhibited a more pronounced reduction, reaching 36 pct. This can be attributed to the fact that AR-A, characterized by fine equiaxed grains and a strong basal texture, is more conducive to the activation of TTs. The mechanical properties of C200-A were synergistically improved, with a 27 pct increase in ultimate tensile strength (UTS), a 50 pct increase in yielding strength (YS), and a 21 pct increase in elongation, and the homogeneous plastic deformation stage is increased significantly. The reason is the significant activation of basal < a > slip and the synergistic effect of multiple dynamic recrystallization (DRX) mechanisms to refine grain size by 41 pct. The elongation of C200-B decreased by 20 pct. The main reason is related to the DRX mechanism. The grain refinement of the coarse grain region mainly via continuous dynamic recrystallization (CDRX) and the accompanied abnormal grain growth of the fine grain region, causing grain homogenization. High plasticity due to the AR-B heterogeneous structure then disappears. Therefore, it is suggested that Mg sheets with fine equiaxed grains and strong basal texture is more readily accessible to obtain good comprehensive mechanical properties via pre-setting TTs.