(山东工业大学材料科学与工程学院，济南 250061)
摘 要: 利用DSC，SEM和X射线衍射等手段，分析了硼对纯铝及亚共晶Al-Si合金的细化作用。发现在纯铝中，AlB2分布在铝的晶界上，无细化作用；而在Al-Si合金中， AlB2具有细化 α(Al)晶粒的性能。分析认为，在Al-Si 加硼的熔体中，AlB2虽不能作α(Al) 的核心，但它为Si的析出提供形核衬底，随温度的下降， α(Al)在Si 相上形核，达到细化的目的。
关键字: 亚共晶Al-Si合金；细化作用；形核；衬底
（College of Materials Science and Engineering, Shandong University of Technology, Ji'nan 250061, P. R. China）
Abstract:Refining effect of boron on the hypoeutectic Al-Si alloys and pure aluminum has been studied with SEM and XRD. The results indicate that in pure aluminum AlB2 segregates on the grain boundary without refining effect; and in Al-7Si alloys AlB2 compound can refine α(Al) grains . In Al-Si melt added boron melt, although AlB2 does not take part directly in the nucleation process, it provides a substrate for nucleation of silicon on which subsequently nucleates α(Al) with the decrease of temperature.
Key words: hypoeutectic Al-Si alloys; refining effect; substrates; nucleation
