Modeling the Flow of Molten Silicon in Porous Carbon Preforms and the Subsequent Formation of Silicon Carbide
Ceramic matrix composites (CMCs) are being considered for a broad range of aerospace applications that include various structural components for the aircraft engine and the space shuttle main engine. Use of silicon-based CMCs which have high thermal conductivity, allows for improvements in fuel efficiency due to increased engine temperatures and pressures, which in turn generate more power and thrust. Furthermore, CMCs offer significant potential for raising the thrust-to-weight of gas turbine engines by tailoring directions of high specific reliability using design-based fiber architecture. One of the low-cost processing techniques for the silicon-based CMCs is the reactive melt infiltration [1] of silicon into the preform of carbon-coated silicon carbide fiber. However, fabrication of high performance SiC/SiC composites requires a deeper understanding of the infiltration kinetics such that fibers are protected from adverse reaction with the molten metal, that the preform is thoroughly infiltrated, and that there is no residual silicon left unreacted.