In the present study, the solidification pathway, microstructure and thermal conductivity of Fe-rich Al–x Si (x = 5, 7, 9, wt%, the same below) alloys were systematically investigated. The results showed that the thermal conductivity was firstly improved and then decreased with Fe content increasing. The improvement and decreasing rate of thermal conductivity was related to the Si content. The change of thermal conductivity was closely related to the change of microstructure and solidification pathway. The addition of Fe element resulted to the precipitation of ternary β (Al₅SiFe) phase (β_T) and binary β phase (β_B). The precipitation of β_T was benefited to improve the thermal conductivity. On the contrast, the precipitation of β_B was prone to deteriorate the thermal conductivity. The precipitation amount of β_T phase and β_B phase was related to the critical value of Fe content (Fe_crit). The calculation results showed that the Fe_crit of Al–x Si alloys was about 0.20% (5% Si), 0.29% (7% Si) and 0.38% (9% Si), respectively. When the Fe content was less critical value (Fe_crit), the precipitation amount of β_T phase was increased by Fe increasing. Furthermore, when the Fe content was more than Fe_crit, the precipitation amount of β_T phase was changed slightly, and the precipitation amount of β_B phase continued to increase with Fe content increasing.

在本研究中，系统地研究了富铁的Al– x Si（x  = 5、7、9 ，wt％，下同）合金的凝固途径，显微组织和热导率。结果表明，随着Fe含量的增加，导热系数先升高后降低。导热率的提高和降低速率与Si含量有关。导热系数的变化与组织和凝固途径的变化密切相关。加入Fe元素导致三元的析出β（铝₅的SiFe）相（β _Ť）和二进制β相（β_乙）。的沉淀β_牛逼是受益于提高热传导率。的对比度，沉淀β_乙是易于恶化的热导率。的析出量β _Ť相和β_乙相有关Fe含量（Fe的临界值_爆击）。计算结果表明，Al– x Si合金的Fe_临界分别约为0.20％（5％Si），0.29％（7％Si）和0.38％（9％Si）。当Fe的含量较少的临界值（FE_爆击），的析出量β _Ť铁的增加增加了相的含量。此外，当Fe的含量超过铁_爆击，的析出量β _Ť相略有改变，和的析出量β_乙阶段持续增加随Fe含量增加。