Pressure infiltration of liquid aluminium into packed SiC particulate with a bimodal size distribution
Pressure infiltration of liquid aluminium into packed SiC particulate with a bimodal size distribution
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DOI：
10.1016/s1359-6454(01)00348-2
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发表时间：
2002-01-22
期刊：
影响因子：
9.4
通讯作者：
Narciso, J
中科院分区：
文献类型：
--
作者：
Molina, JM;Saravanan, RA;Narciso, J
将液态铝渗透到平均直径为170和16微米的SiC颗粒混合和填充预制体中，制备了高体积分数复合材料。当粗颗粒含量为67%时，得到最大颗粒体积分数（0.74）。预坯密实度随粗颗粒百分比的变化可以用一个简单的模型来很好地理解。实验结果表明，阈值压力主要由细颗粒的局部致密度决定，这一结果与计算颗粒体积分数的模型相一致。用有机液体（聚乙二醇）无压渗透的方法评价了压片的渗透性，并将结果与铝的渗透性进行了比较。这两个数据集在质量上一致，即粗颗粒的百分比较低。然而，虽然用有机液体获得的渗透率显示具有最大致密性的预制体的最小值（大约是细颗粒获得的值的一半），但在铝的情况下，该预制体的渗透率（以及其他具有最大致密性的预制体）显着更高。这是由于在铝的加压渗透过程中，由颗粒偏析引发的颗粒的推动。(C) 2002材料学报Elsevier Science Ltd.出版。版权所有。
High volume fraction composites were produced by infiltrating liquid aluminium into preforms made by mixing and packing SiC particles with average diameters of 170 and 16 mum. The maximum particle volume fraction (0.74) was attained for a mixture having 67% of coarse particles. The variation of the preform compactness with the percentage of coarse particles can be reasonably well understood in terms of a simple model. The experimental results indicate that the threshold pressure is mainly determined by the local compactness of fine particles, a result which is shown to be compatible with the model used to calculate the particle volume fraction. The permeability of the compacts was also evaluated by means of pressureless infiltration with an organic liquid (polyethylene glycol) and the results were compared with those obtained with aluminium. The two data sets qualitatively agree for low percentages of coarse particles. However, while the permeability obtained with the organic liquid shows a minimum for preforms having the maximum compactness (roughly half the value obtained for fine particles), in the case of aluminium, the permeability for that preform (and others having a compactness around the maximum) was significantly higher. This was ascribed to the pushing of particles during pressurised infiltration of aluminium, triggered by particle segregation. (C) 2002 Acta Materialia Inc. Published by Elsevier Science Ltd. All rights reserved.