ABSTRACT During centrifugal casting of Al-Mg2Si hypereutectic cylinders, the light Mg2Si particles are commonly segregated in centripetal direction towards the inner periphery. In order to change this inevitable centripetal segregation of Mg2Si particles, some amounts of tin up to 8 wt pct were added to Al-15wt.% Mg2Si alloy to enhance the formation of Mg2Si(1−x)Snx particles with variant stoichiometry thus variant density. XRD, EDS, optical metallography and hardness measurements were used to evaluate the stoichiometry and segregation patterns of in situ formed Mg2Si(1−x)Snx particles. According to the results, the cylinder containing 6 wt pct Sn illustrates a rather uniform distribution of particles thus hardness in all radial sections. However, the cylinders with higher amounts of Sn exhibit a radial segregation of Mg2Si(1−x)Snx particles in centrifugal direction towards the outer periphery. The results are interpreted in view of the Stokes’ law and the difference in density of the particles and the melt.

中文翻译：

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原位 Al-Mg2Si(1-x)Snx 复合材料的离心铸造：径向偏析研究

摘要 在离心铸造 Al-Mg2Si 过共晶圆柱体过程中，轻质 Mg2Si 颗粒通常在向心方向朝内周边偏析。为了改变这种不可避免的 Mg2Si 颗粒向心偏析，向 Al-15wt.% Mg2Si 合金中添加了一些高达 8wt% 的锡，以增强具有不同化学计量比的 Mg2Si(1-x)Snx 颗粒的形成，从而改变密度. XRD、EDS、光学金相和硬度测量用于评估原位形成的 Mg2Si(1-x)Snx 颗粒的化学计量和偏析模式。根据结果​​，包含 6 wt pct Sn 的圆柱体表明颗粒分布相当均匀，因此在所有径向截面中都有硬度。然而，具有较高 Sn 量的圆柱表现出 Mg2Si(1-x)Snx 颗粒在离心方向上向外周边径向偏析。根据斯托克斯定律以及颗粒和熔体的密度差异来解释结果。