Towards optimization of SiC/CoSi2 composite material manufacture via reactive infiltration: Wetting study of Si-Co alloys on carbon materials

Among manufacture techniques for SiC ceramics, reactive infiltration has proven to be the most efficient. However, materials manufactured with this technique present minimum 10% of unreacted silicon. Si hinders the performance of the material. The replacement of Si with a MexSiy can improve the performance of the composite. Since Me-Si alloys wet carbon materials, they are suitable candidates to be used as infiltrants in SiC/MexSiy composite production via reactive infiltration. To optimize the process, it is necessary to identify the mechanisms involved in infiltration and the parameters governing them. A basic wetting study can provide a clear understanding of the operative mechanisms and allow obtaining accurate parameters. In this work, the wetting behavior of silicon-cobalt alloys on carbon materials was studied using the sessile drop technique. The influence of temperature, composition and carbon crystallinity was evaluated, observing a strong dependence of process kinetics and reactivity with temperature and carbon crystallinity.