The extrudability, microstructural characteristics, and tensile properties of the Mg–5Bi–3Al (BA53) alloy are investigated herein by comparing them with those of a commercial Mg–8Al–0.5 Zn (AZ80) alloy. When AZ80 is extruded at 400 °C, severe hot cracking occurs at exit speeds of 4.5 m/min or more. In contrast, BA53 is successfully extruded without any surface cracking at 400 °C and at high exit speeds of 21–40 m/min. When extruded at 3 m/min (AZ80–3) and 40 m/min (BA53–40), both AZ80 and BA53 exhibited completely recrystallized microstructures with a 〈10–10〉 basal texture. However, BA53–40 has a coarser grain structure owing to grain growth promoted by the high temperature in the deformation zone. AZ80–3 contains a continuous network of Mg₁₇Al₁₂ particles along the grain boundaries, which form via static precipitation during natural air-cooling after the material exits the extrusion die. BA53–40 contains coarse Mg₃Bi₂ particles aligned parallel to the extrusion direction along with numerous uniformly distributed fine Mg₃Bi₂ particles. AZ80–3 has higher tensile strength than BA53–40 because the relatively finer grains and larger number of solute atoms in AZ80–3 result in stronger grain-boundary and solid-solution hardening effects, respectively. Although BA53 is extruded at a high temperature and extrusion speed of 400 °C and 40 m/min, respectively, the extruded material has a high tensile yield strength of 188 MPa. This can be primarily attributed to the large particle hardening effect resulting from the numerous fine Mg₃Bi₂ particles.

本文通过将 Mg-5Bi-3Al (BA53) 合金与商用 Mg-8Al-0.5 Zn (AZ80) 合金进行比较，研究了它们的可挤压性、微观结构特征和拉伸性能。当 AZ80 在 400 °C 下挤出时，在 4.5 m/min 或更高的出口速度下会发生严重的热裂纹。相比之下，BA53 在 400 °C 和 21–40 m/min 的高出口速度下成功挤出，没有任何表面开裂。当以 3 m/min (AZ80–3) 和 40 m/min (BA53–40) 挤压时，AZ80 和 BA53 均表现出完全再结晶的微观结构，具有 <10–10> 基底织构。然而，由于变形区高温促进了晶粒长大，BA53-40 具有较粗的晶粒结构。_{AZ80–3 包含 Mg 17} Al ₁₂的连续网络沿晶界的颗粒，在材料离开挤压模具后自然空气冷却过程中通过静态沉淀形成。BA53–40 包含平行于挤压方向排列的粗 Mg ₃ Bi ₂颗粒以及大量均匀分布的细 Mg ₃ Bi ₂粒子。AZ80-3 具有比 BA53-40 更高的抗拉强度，因为 AZ80-3 中相对较细的晶粒和较多的溶质原子分别导致更强的晶界和固溶硬化效应。尽管 BA53 分别在 400 °C 和 40 m/min 的高温和挤压速度下挤压，但挤压材料具有 188 MPa 的高拉伸屈服强度。这主要归因于由大量细小的 Mg ₃ Bi ₂颗粒引起的大颗粒硬化效应。