针对当前3003铝合金力学性能偏低的难题，本文借助热力学模拟、SEM、EBSD及TEM等系统研究了3003铝合金的凝固行为及均质化温度对铝合金微观组织的影响规律，并揭示了不同状态下微观组织与该铝合金力学性能的关系。凝固初期，Mn元素在固相中的含量约为0.94%；固相分数为约50%时，固相中Mn含量达到1.20%，此时α-AlMnFeSi相开始生成；凝固末期，固相中Mn含量降低到约0.33%；经555±5 ℃均质化后，试样晶内析出的第二相尺寸较小，体积分数较高，晶粒边缘区域PFZ平均宽度较窄。经555±5 ℃均质化的试样中析出相对屈服强度的贡献约为28.5 MPa；比经600±5 ℃均质化试样中析出相的强度贡献高约23 MPa，即析出相是造成试样之间屈服强度差异的重要原因。本文的研究结果将为工业领域规模化生产高强度3xxx系铝合金提供理论依据。

To eliminate the urgent problem of insufficient mechanical properties in 3003 aluminum alloys, this work systematically investigates their solidification behaviors, as well as the influence of homogenization temperature on both microstructure and mechanical properties by using thermodynamic simulation, SEM, EBSD, and TEM. During the initial solidification stage, the Mn content in the FCC phase is approximately 0.94%. When the solid phase fraction reaches about 50%, the Mn content in the FCC phase increases to ~1.20%, at which point the α-AlMnFeSi phase begins to form. On the contrary, by the end of solidification (with a solid phase fraction of about 95%), the Mn content in the FCC phase decreases to 0.33%. After homogenization heat treatment, multitudinous second-phase particles precipitate within the grains. For the sample homogenized at 555±5 ℃, the intragranular precipitates are smaller and have a higher volume fraction, compared to the sample homogenized at 600±5 ℃. In addition, the average width of PFZ at the grain margin in the former sample is narrower. Furthermore, the contribution of precipitates to the yield strength of the 3003 aluminum alloy homogenized at 555±5 ℃ is about 28.5 MPa; which is approximately 23 MPa higher than that of the sample homogenized at 600±5 ℃. This difference matches well with the actual measured value, indicating that the precipitated phase is the main factor responsible for the difference in yield strength between the 3003 aluminum alloys homogenized at 555±5 ℃ and 600±5 ℃. This study will provide a theoretical basis for the large-scale industrial production of high-strength 3xxx series aluminum alloys.