Abstract

Insufficient understanding of the nature of the interfacial interaction of reinforcing particles with the matrix alloy during repeated remelting of cast composite materials is one of the problems that limit the increase in the volume of their industrial application. This work is aimed at establishing the effect of repeated remelting of AK12 + 10 vol % SiC aluminum matrix composites on the retention and chemical stability of silicon carbide reinforcing particles. It is shown that an increase in the number of remelting iterations was not accompanied by the appearance of new phases at the interfaces between particles and the matrix, which indicates the stability of the SiC reinforcing phase in aluminum–silicon melts under the considered temperature–time and concentration conditions. During repeated remelting of aluminum matrix composites with silicon carbide, the degree of particle distribution uniformity shifts toward a more uniform distribution (on average 0.81046 at the first iteration of remelting, 0.6901 at the second, and 0.5609 at the third) and some decrease in their average sizes occurs (from 70.74 µm at the first iteration to 65.76 µm at the second and 61.21 µm at the third), apparently owing to particle fragmentation, leading to an increase in the amount of a finer fraction. At the same time, the share of the area occupied by particles in the segments of the section under consideration remains practically unchanged (10.9293, 10.9607, and 11.6483% in the first, second, and third iterations of remelting, respectively). In the course of repeated remelting of aluminum matrix composites of the Al–SiC system, processes of redistribution of reinforcing particles occur, leading to the destruction of agglomerates even in the absence of intensive mixing by an impeller. Because of this, the uniformity of particle distribution in the structure of ingots of secondary aluminum matrix composites can be significantly improved.

中文翻译：

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多次重熔过程中铸铝基复合材料结构和相组成的形成

摘要

对铸造复合材料反复重熔过程中增强颗粒与基体合金界面相互作用的性质了解不足是限制其工业应用量增加的问题之一。这项工作旨在确定 AK12 + 10 vol% SiC 铝基复合材料的重复重熔对碳化硅增强颗粒的保留和化学稳定性的影响。结果表明，重熔次数的增加并没有伴随着颗粒和基体之间界面处新相的出现，这表明在考虑的温度-时间下，铝-硅熔体中 SiC 增强相的稳定性和浓度条件。碳化硅铝基复合材料在反复重熔过程中，颗粒分布均匀度向更均匀分布方向移动（第一次重熔平均为0.81046，第二次为0.6901，第三次为0.5609），颗粒分布均匀度有所下降出现平均尺寸（从第一次迭代的 70.74 µm 到第二次迭代的 65.76 µm 和第三次迭代的 61.21 µm），显然是由于粒子碎片，导致更细部分的数量增加。同时，在所考虑的截面中，粒子占据的面积份额几乎保持不变（在第一次、第二次和第三次重熔迭代中分别为 10.9293、10.9607 和 11.6483%）。在Al-SiC系铝基复合材料的反复重熔过程中，发生增强颗粒的重新分布过程，即使在没有叶轮充分混合的情况下也会导致附聚物的破坏。正因为如此，可以显着提高二次铝基复合材料铸锭结构中颗粒分布的均匀性。