In this paper, the effect of Er addition (0.2, 0.5, 0.65, 0.8, 1.0, and 1.5 wt. %) on the microstructure evolution and tensile properties of as-cast hypereutectic Al-10Si-0.8Fe alloy was investigated. The phases and their morphologies in these alloys were identified by XRD and SEM equipped with EDX with the help of metallographic analysis techniques; the length of the secondary phase (LSP) and secondary dendrite arm spacing (SDAS) of α-Al grain were quantified. The results indicated that the second phases (primary Si, eutectic Si, and iron-rich phases) and α-Al grain were significantly refined when the addition of Er increased from 0 to 0.8 wt. %. The mean LSP and SADS values were decreased to a minimum value when the Er addition reached 0.8 wt. %. However, the second phases and α-Al grain became coarser when the level of Er increased more than 0.8 wt. %. The analysis of XRD shows that Er mainly exists in the form of Er2Si compound. The microstructure modification also has a significant effect on the mechanical properties of the alloy. The yield strength (YS), ultimate tensile strength (UTS), and elongation (EL) increase from 52.86 MPa, 163.84 MPa, and 3.45% to 71.01 MPa, 163.84 MPa, and 5.65%, respectively. From the fracture surface, the promotions of mechanical properties are due to the dispersion and pinning reinforcement caused by the Er2Si phase.

中文翻译：

---

亚共晶Al-10Si-0.8Fe-XEr合金的显微组织和力学性能研究

在本文中，研究了 Er 的添加量（0.2、0.5、0.65、0.8、1.0 和 1.5 wt.%）对铸态过共晶 Al-10Si-0.8Fe 合金的组织演变和拉伸性能的影响。在金相分析技术的帮助下，这些合金中的物相及其形貌通过配备 EDX 的 XRD 和 SEM 进行鉴定；量化了 α-Al 晶粒的二次相长度 (LSP) 和二次枝晶臂间距 (SDAS)。结果表明，当 Er 的添加量从 0 增加到 0.8 wt 时，第二相（初生 Si、共晶 Si 和富铁相）和 α-Al 晶粒显着细化。%。当 Er 添加量达到 0.8 wt 时，平均 LSP 和 SADS 值降低到最小值。%。然而，当 Er 含量增加超过 0 时，第二相和 α-Al 晶粒变得更粗大。8 重量 %。XRD分析表明Er主要以Er2Si化合物的形式存在。显微组织的改变对合金的力学性能也有显着影响。屈服强度 (YS)、极限抗拉强度 (UTS) 和伸长率 (EL) 分别从 52.86 MPa、163.84 MPa 和 3.45% 增加到 71.01 MPa、163.84 MPa 和 5.65%。从断裂面看，力学性能的提升是由于 Er2Si 相引起的弥散和钉扎增强。和 5.65%，分别。从断裂面看，力学性能的提升是由于 Er2Si 相引起的弥散和钉扎增强。和 5.65%，分别。从断裂面看，力学性能的提升是由于 Er2Si 相引起的弥散和钉扎增强。