In this study, a novel high-pressure die-cast Al-1.5Fe-1Ni alloy with high thermal conductivity was designed, and the relationship between its microstructure and properties was discussed. Firstly, based on the effect of alloying elements on the electrical resistivity of aluminum and phase diagrams, we designed Al-1.5Fe-xNi (x = 0, 0.5, 1, and 1.5) ternary alloys and investigated the effect of Ni content on the microstructure and thermal conductivity. The phase in the Al-1.5Fe-xNi alloy (x = 0.5, 1, and 1.5) transforms to the Al₉NiFe phase at room temperature because of the solid transformation from Al₁₃(Fe, Ni)₄ to Al₉NiFe. When the Ni content is below 1 wt.%, the alloy has a hypoeutectic composition. When the Ni content increases to 1.5 wt.%, needle-like primary phases are formed. The eutectic of the Al-1.5Fe-xNi alloy consists of a fibrous inner eutectic phase and a lamellar outer eutectic phase. The morphological transition of the eutectic Al₉NiFe phase is attributed to the element Ni enrichment in the remaining liquid. Based on the property’s evolution, an Al-1.5Fe-1Ni die-cast alloy was prepared. The microstructure of the die-cast Al-1.5Fe-1Ni alloy from surface to center is heterogeneous, and the skin layers exhibit different patterns. The formation of these skin layers depends on the cooling rate. The die-cast alloy exhibits a high thermal conductivity of over 190 W m⁻¹ K⁻¹ and an elongation of over 15%. A new thermal conductivity model for die-cast alloys based on the microstructural characteristics reveals the crucially harmful effect of solute concentration in the matrix on the thermal conductivity of die-cast Al-1.5Fe-1Ni alloy. The skin layer has a minimal effect on thermal conductivity. Primary α-Al grains with low solute concentrations promote alloy deformation, leading to quite high elongation. The study will provide new insights into the microstructure evolution and the relationship between microstructure and properties of Al-Fe-Ni alloys with high thermal conductivity.

中文翻译：

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新开发的具有高导热性的高压压铸 Al-1.5Fe-1Ni 合金：设计、微观结构和性能

本研究设计了一种新型高导热率的高压压铸 Al-1.5Fe-1Ni 合金，并讨论了其微观组织与性能之间的关系。首先，根据合金元素对铝电阻率和相图的影响，我们设计了 Al-1.5Fe-x Ni （x = 0、0.5、1 和 1.5） 三元合金，并研究了 Ni 含量对微观组织和热导率的影响。Al-1.5Fe-x Ni 合金（x = 0.5、1 和 1.5）中的相在室温下转变为 Al₉NiFe 相，因为固体从 Al₁₃（Fe， Ni）₄ 转变为 Al₉NiFe 相。当 Ni 含量低于 1 wt.% 时，合金具有亚共晶成分。当 Ni 含量增加到 1.5 wt.% 时，形成针状初级相。Al-1.5Fe-x Ni 合金的共晶由纤维状内共晶相和层状外共晶相组成。共晶 Al₉NiFe 相的形态转变归因于剩余液体中元素 Ni 的富集。根据该特性的演变，制备了 Al-1.5Fe-1Ni 压铸合金。压铸 Al-1.5Fe-1Ni 合金从表面到中心的微观结构是异质的，表皮层呈现不同的图案。这些皮肤层的形成取决于冷却速度。压铸合金具有超过 190 W ^{m-1 K-1} 的高导热率和超过 15% 的伸长率。基于微观结构特性的压铸合金热导率模型揭示了基体中溶质浓度对压铸 Al-1.5Fe-1Ni 合金热导率的严重有害影响。 表皮层对导热性的影响最小。溶质浓度低的初级 α-Al 晶粒会促进合金变形，从而导致相当高的伸长率。该研究将为高导热率 Al-Fe-Ni 合金的微观结构演变以及微观组织与性能之间的关系提供新的见解。