Abstract

The microstructure, the grain structure, and the elemental composition of the Al–11.8Si–0.6Mg–0.4Mn–0.6Fe–0.8Ni–1.7Cu alloy (wt %) fabricated at melt cooling rates of 10² and 10⁵ K/s have been investigated by scanning electron microscopy, electron backscattered diffraction, and electron-probe microanalysis. An increase in the cooling rate of the melt from 10² to 10⁵ K/s refines the structural constituents of the alloy (grain sizes, intermetallic particle sizes, silicon particle sizes) by two orders of magnitude. The foil formed at a melt cooling rate of 10⁵ K/s has a layered microstructure in the cross-section. High-rate solidification provides a constant concentration of elements in the layers. The formation of nanoinclusions in the foil layer adjacent to the mold has been explained. The composition of submicron (up to 200 nm) compounds localized at the boundaries of eutectic grains in the layer at the freely solidified side has been identified.

中文翻译：

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熔体冷却速率对Mg、Mn、Fe、Ni和Cu掺杂Al-Si合金微观组织的影响

摘要

^{在 10 2}和 10 ⁵ K/的熔体冷却速率下制备的 Al-11.8Si-0.6Mg-0.4Mn-0.6Fe-0.8Ni-1.7Cu 合金的显微组织、晶粒结构和元素组成 (wt %) s 已经通过扫描电子显微镜、电子背散射衍射和电子探针显微分析进行了研究。将熔体的冷却速率从 10 ²提高到 10 ⁵ K/s，可将合金的结构成分（晶粒尺寸、金属间化合物颗粒尺寸、硅颗粒尺寸）细化两个数量级。^{在 10 5}的熔体冷却速率下形成的箔K/s在横截面上具有层状微观结构。高速凝固提供了层中元素的恒定浓度。已经解释了在与模具相邻的箔层中纳米夹杂物的形成。已经确定了位于自由凝固侧层中的共晶晶粒边界的亚微米（最高 200 nm）化合物的成分。