Al-Ce 基合金具有低密度、优异的抗粗化性能和良好的铸造性能，是 200~450 ℃范围内具有稳定服役能力的潜 在 材 料 。 本文 制 备 了 成 分 为 Al-10%Ce-5%Ni-4%Cu(质量 分 数 ，简称 ACNC)的合 金 ，系统 研 究 了 其 在 铸 态 及 等温时 效过程中的显微组织演变，测试了其在室温和高温下的拉伸性能，并探讨了相关强化机制。 结果表明，ACNC 合金呈现亚共晶组织，由初生 α-Al 枝晶、“长条状或梅花状”的 Al3Ni 相、“鱼骨状”的 Al11(Ce, Cu)3 相以及共晶团组成。 共晶团内 Al3CeCu 与 Al3Ni 相以 纤 维 状 相 互 缠 结 。 在 450 ℃等温 时 效 24 h 后 ，共晶 相 缓 慢 粗 化 ，其宽 度 从(154±64) nm增至 (519±241) nm，间距 从(380±155) nm 增至(1 029±511) nm，合金 硬 度 随 之 逐 渐 下 降 。 而在 590 ℃过时 效 5h 后 ，Al3Ni 与Al3CeCu 相迅速球化，导致硬度急剧降低。 合金在室温、200、300 和 400 ℃下的屈服强度分别为(136±7) MPa、(121±2) MPa、(86±1) MPa 和(45±2) MPa。

Al-Ce-based alloys, characterized by low density, excellent coarsening resistance and good castability, are promising materials for stable service in the temperature range of 200~450 ℃ .In this study, an alloy with a nominal composition of Al-10Ce-5Ni-4Cu (wt.%, named ACNC) was prepared. The microstructure evolution in the as-cast sample and during isothermal aging was systematically investigated, and its tensile properties at room and elevated temperatures were tested, along with the underlying strengthening mechanisms. The results indicate that the ACNC alloy has a hypoeutectic microstructure, consisting of primary α-Al dendrites, “rod-like or plum-blossom-like” Al3Ni phases, “fishbone-like” Al11(Ce, Cu)3 phases, and eutectic colonies. Within the eutectic colonies, the Al3CeCu and Al3Ni phases are entangled in a fibrous manner. After isothermal aging at 450 ℃ for 24 h, the width of the eutectic phases increase from (154±64) nm to (519±241) nm, and the eutectic spacing expandes from (380±155) nm to (1 029±511) nm, accompanied by aprogressive decrease in hardness. In contrast, severe overaging at 590 ℃ for 5 h leads to rapid spheroidization of the Al3Ni and Al3CeCu phases, resulting in a sharp decrease in hardness. The yield strengths of the alloy at room temperature, 200, 300 and 400 ℃ are measured as (136±7) MPa, (121±2) MPa, (86±1) MPa, and (45±2) MPa, respectively.