Interphase behavior of mini C/SiC composites prepared via reactive melt infiltration

Because of inevitable reaction between molten silicon and carbon fibers during reactive melt infiltration (RMI) method, mechanical properties of C/SiC composites may be affected. In this work, TaC interphase was prepared in C/SiC composites to protect the carbon fibers from corrosion by molten silicon. The microstructure of carbon fibers with different interphases was systematically investigated, and the optimum thickness was selected to prepare mini C/SiC composites. Study the corrosion mechanism of molten silicon based on the corrosion of interphases and carbon fibers. The results showed that the damage degree of PyC interphase and carbon fibers decreased with the increase of TaC thickness. In addition, compared with mini composites without TaC interphase, mini composites with ∼300 nm TaC interphase can withstand a fracture load increase of about 26 %. Finally, the presence of carbon fiber and PyC interphase in TEM further confirmed the great corrosion resistance of TaC interphase to molten silicon.