Processes for fabricating ceramic matrix composites

A process for melt-infiltrating a partially densified ceramic matrix composite, comprising the steps of:

• disposing in a chamber of a thermal processing apparatus a partially densified ceramic matrix composite comprising a ceramic matrix including at least silicon carbide and at least one oxide phase precursor;
• introducing at least one gas into the thermal processing apparatus;
• elevating a temperature of the chamber to cause a reaction between the silicon carbide and the least one gas;
• achieving a chemical equilibrium of the gases within the chamber;
• identifying a gas regime for minimizing the liberation of SiO and formation of SiO2;
• maintaining a temperature and CO2:CO ratio of the identified gas regime within the chamber;
• and
• melt-infiltrating the partially densified ceramic matrix composite with the at least one oxide phase precursor to form a molten oxide ceramic matrix composite comprising a matrix including a silicon carbide phase and an oxide phase.

A ceramic matrix composite fabricated according to a process comprising the following steps:

• disposing a partially densified ceramic matrix composite comprising a ceramic matrix including at least one oxide phase precursor within an opening of a vessel;
• disposing a mixture of one or more of silicon carbide and silicon dioxide within the opening to surround the partially densified ceramic matrix composite;
• sealing the vessel and capturing oxygen gas present within the vessel;
• disposing the sealed vessel in a chamber of a furnace;
• generating an inert atmosphere within the chamber;
• heating the chamber to a temperature proximate to or greater than a melting point of the at least one oxide phase precursor;
• liberating SiO gas within the sealed vessel;
• achieving an equilibrium vapor pressure of SiO gas within the sealed vessel;
• and,
• melt-infiltrating the partially densified ceramic matrix composite with the at least one oxide phase precursor to form a molten oxide ceramic matrix composite comprising a silicon carbide phase and an oxide phase.

A ceramic matrix composite fabricated according to a process comprising the following steps:

• disposing in a chamber of a thermal processing apparatus a partially densified ceramic matrix composite comprising a ceramic matrix including at least silicon carbide and at least one oxide phase precursor;
• introducing at least one gas into the thermal processing apparatus;
• elevating a temperature of the chamber to cause a reaction between the silicon carbide and the least one gas;
• achieving a chemical equilibrium of the gases within the chamber;
• identifying a gas regime for minimizing the liberation of SiO and formation of SiO2;
• maintaining a temperature and CO2:CO ratio of the identified gas regime within the chamber;
• and
• melt-infiltrating the partially densified ceramic matrix composite with the at least one oxide phase precursor to form a molten oxide ceramic matrix composite comprising a matrix including a silicon carbide phase and an oxide phase.