Study on the Effect of Process Parameters on the Pressureless Impregnation Behavior of SiC/Al Composites

Abstract Preforms with a volume fraction of 60% were prepared by the compression molding method. SiC/Al composites were prepared by the pressureless infiltration process. Analytical characterization of SiC preforms and SiC/Al composites was obtained using metallurgical microscopy, X-ray diffractometry (XRD), scanning electron microscopy (SEM), etc. The effects of magnesium additives and infiltration atmospheres on the infiltration behavior of aluminum alloy melts and the infiltration characteristics of aluminum alloys in prefabricated bodies were systematically investigated. The results of the study show that: Magnesium as an infiltration aid can remove the oxide film on the surface of the aluminum alloy block, which is conducive to the infiltration of the aluminum alloy melt in the prefabricated body. High purity nitrogen is essential for the success of pressureless infiltration. The reaction of magnesium with the surface of SiC particles during pressureless infiltration improves wettability, which promotes the infiltration of the aluminum alloy melt into the precast.