Abstract

The microstructure, the phase composition, the component distribution, and the grain structure of the commercial eutectic Al–12.2 Si–0.2 Fe (at %) silumins formed at cooling rates of 10² and 10⁵ K/s are studied. Three phases are detected in the alloy after solidification at both cooling rates: α-aluminum, silicon, and an iron-containing phase. The bulk samples have a heterogeneous dendritic structure with large dendrites of an aluminum-based solid solution, and a eutectic lamellar mixture of aluminum and silicon filling the interdendritic space. The melt-quenched foils are characterized by a homogeneous microstructure over the thickness; however, they have a layered structure. The rapidly solidified foils also have a homogeneous granular structure through the thickness and no pronounced texture. The mechanisms of solidification and microstructure formation are proposed for both the bulk samples and the melt-quenched foils.

中文翻译：

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熔融淬火的Al–12.2Si–0.2Fe合金的结构形成

摘要

冷却速率为10 ²和10 ^5时形成的商业低共熔Al-12.2 Si-0.2 Fe（at％）硅铝氧体的微观结构，相组成，成分分布和晶粒结构研究了K / s。在两种冷却速率下，凝固后的合金中检测到三相：α-铝，硅和含铁相。本体样品具有异质的树枝状结构，其中铝基固溶体具有大的树枝状结构，并且铝和硅的共晶层状混合物充满了树枝状结构间的空间。熔融淬火的箔片的特征是在整个厚度上均一的微观结构。但是，它们具有分层结构。快速固化的箔在厚度上也具有均匀的颗粒结构，没有明显的质地。提出了块状样品和熔融淬火箔的凝固和微观结构形成的机理。