Effect of Mg and Si in the aluminum on the thermo-mechanical properties of pressureless infiltrated SiCp/Al composites
Effect of Mg and Si in the aluminum on the thermo-mechanical properties of pressureless infiltrated SiCp/Al composites
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DOI：
10.1016/j.compscitech.2006.11.006
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发表时间：
2007-08
影响因子：
9.1
通讯作者：
S. Ren;Xin-Bo He;X. Qu;I. S. Humail;Yan Li
中科院分区：
文献类型：
--
作者：
S. Ren;Xin-Bo He;X. Qu;I. S. Humail;Yan Li
研究了在铝中添加镁和硅对无压浸渗SiCp/Al复合材料热机械性能的影响。结果表明，当硅含量低于6wt%或镁含量低于4wt%时，复合材料的热物理性能较差，这是由于铝与硅之间的润湿性差导致复合材料中的气孔率较高所致。增加铝中的硅含量可以提高复合材料的弹性模量、热尺寸稳定性和导热系数，降低复合材料的热膨胀系数。然而，当硅含量超过12wt%时，复合材料的导热系数和弯曲强度都会降低。铝中镁的最佳加入量为4~8wt%，此时复合材料具有较好的热机械性能。然而，当镁含量增加到8wt%以上时，由于镁的压力较低，导致复合材料的气孔率较高，导致热机械性能下降。用扫描电子显微镜和透射电子显微镜对复合材料的微观结构进行了研究，以更好地了解硅和镁的添加对其性能的影响。
The effect of adding Mg and Si to aluminum on the thermo-mechanical properties of pressureless infiltrated SiCp/Al composites was investigated. The results showed that, when the Si content was lower than 6wt% or the Mg content was lower than 4wt%, the composites showed poor thermo-physical properties because of higher porosity in the composites resulting from the poor wettability between Al and Si. Increasing the Si content to the aluminum can enhance the elastic modulus, thermal dimensional stability and thermal conductivity of the composites and reduce the coefficient of thermal expansion (CTE) of the composites. However, excessive Si beyond 12wt% can reduce the thermal conductivity and bending strength of the composites. An optimum content of Mg addition to aluminum was found to be 4–8wt%, at which the composites exhibited good thermo-mechanical properties. However, as the Mg content was increased beyond 8wt%, the higher porosity in the composites resulting from the lower pressure of the magnesium led to lower thermo-mechanical properties. The microstructure of such composites was also studied by SEM and TEM to better understand how the addition of Si and Mg affects their properties.