MINIMIZING INFILTRATION TIMES DURING ISOTHERMAL CHEMICAL-VAPOR INFILTRATION WITH METHYLTRICHLOROSILANE

Minimum infiltration times during isothermal chemical vapor infiltrati on were calculated for the formation of a silicon carbide matrix compo site from methyltrichlorosilane (MTS). Several different reaction mode ls were used to describe the SiC deposition kinetics. The results show that the nature of the reaction model has a significant effect on pro cess optimization considerations. It is clear that a simple first-orde r deposition reaction does not accurately describe the infiltration pr ocess, while rate expressions that treat the effect of chlorine-contai ning byproduct gases provide much more accurate predictions, In theory , much shorter infiltration times can be obtained with precursor chemi stries that do not produce Cl-containing gases. The results also provi de guidelines for minimizing infiltration times with MTS.