Effect of Si Content on Melt Infiltration Method of SiCf/SiC-Ti3SiC2

Abstract

SiCf/SiC composites have attracted wide attention as thermo-structural materials owing to its extraordinary properties at elevated temperature. To further improve the toughness of SiCf/SiC, Ti3SiC2 is used as the reinforcement of SiC matrix. In this study, the effect of Si content on the formation of Ti3SiC2 was discussed. The melt Si infiltration method was used to prepare the SiC matrix, whichTi3SiC2phase was in-situ formed from the reaction between TiC, C and Si during the infiltration process. X-ray diffractometry (XRD), scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS) were determined to characterize the phase constitution and microstructure of the matrix. The results demonstrate that the synthesis of Ti3SiC2 was depended on the amount of Si during the molten Si infiltration. The small amount of Si could resulted in the incomplete infiltration reaction. TiSi2 was obtained at the presence of excessive Si. Thus appropriate amount of Si promotes the formation of Ti3SiC2 and improves the purity.