FCC/B2 双相多主元合金因兼具高强度与良好韧性而受到广泛关注，但其在高应变速率下的冲击韧性不足限制了工程应用。 针对这一问题，本研究通过调控 Al/Fe 比例，成功制备了尺寸为 φ100 mm×400 mm、质量为 25 kg 的具有不 同 相 体 积 分 数 的铸 态 AlxCr10Fe53-xNi36Mo1 (x=13,15,17, 原子分数,%) 双相合金，并系统分析了 Al/Fe 比例对凝固组织、相界特征及力学性能的影响。 结果表明，降低 Al/Fe 比例使铸锭的凝固组织由规则层状共晶结构转变为含初生 FCC相枝晶的亚共晶结构，同时 FCC 相的体积分数由 Al17 的 68.1%增加至 Al13 的 93.1%；此外，FCC/B2 界面密度降低并逐渐偏离 K-S 取向关系。 其中，Al13 合金由于较低的 FCC/B2 相界面密度和较高的 FCC 相体积分数，表现出更好的塑性和加工硬化稳定性，其室温拉伸屈服强度为 622 MPa，伸长率为 31.9%；此外，其在室温下冲击功达到 19.62 J，这可归因于其较大的塑性变形能力以及复杂的裂纹扩展路径。

FCC/B2 dual-phase multiprincipal element alloys combine high strength with good ductility, but their insufficient impact toughness under dynamic loading remains a key obstacle to engineering applications. To overcome this limitation, as-cast AlxCr10Fe53-xNi36Mo1 (x=13,15,17 at.%) alloys with different phase volume fractions were designed and fabricated by tuning the Al/Fe ratio, with a size of φ100 mm ×400 mm and a weight of 25 kg, aiming to establish composition-microstructure-property relationships. Microstructural characterization reveals that decreasing the Al/Fe ratio drives a transition from a regular lamellar eutectic structure (Al17) to a hypoeutectic microstructure with primary FCC dendrites (Al13) while simultaneously increasing the FCC phase fraction from 68.1% to 93.1%. In addition, the FCC/B2 interfacial density decreases and gradually deviates from the Kurdjumov-Sachs (K-S) orientation relationship. These structural changes significantly improve the mechanical response: the Al13 alloy achieves the most favourable balance, with ayield strength of 622 MPa, 31.9% tensile ductility, and an impact energy of 19.62 J at room temperature.