摘要 |
A ceramic matrix composite article 10 includes a melt infiltration ceramic matrix composite substrate 20 comprising a ceramic fiber reinforcement material in a ceramic matrix material having a first free silicon proportion, and a melt infiltration ceramic matrix composite outer layer 50 comprising a ceramic fiber reinforcement material in a ceramic matrix material having a second free silicon proportion disposed on an outer surface of at least a portion of the substrate, or a polymer impregnation and pyrolysis ceramic matrix composite outer layer comprising a ceramic fiber reinforcement material in a ceramic matrix material having a second free silicon proportion disposed on an outer surface of at least a portion of the substrate. The second free silicon proportion is less than the first free silicon proportion. |