Method of altering a surface of a ceramic matrix composite to aid in nodule removal

A method of altering a surface of a ceramic matrix composite to aid in nodule removal, the method comprising:

• heating a fiber preform comprising a framework of ceramic fibers to a temperature at or above a melting temperature of silicon;
• during the heating, infiltrating the fiber preform with a molten material comprising silicon, forming an infiltrated fiber preform;
• after the infiltration, cooling the infiltrated fiber preform from the temperature at or above the melting temperature to ambient temperature, and
• during the cooling, exposing the infiltrated fiber preform to a gas comprising nitrogen,
• wherein the exposure to the gas comprising nitrogen occurs during only an initial phase of the cooling, from the temperature at or above the melting temperature of silicon to a second temperature above the ambient temperature, the second temperature being at or above about 1200° C., the exposure to the gas comprising nitrogen being halted at the second temperature, and
• further comprising:
• after reaching the second temperature and halting the exposure to the gas comprising nitrogen, exposing the infiltrated fiber preform to a vacuum or inert gas atmosphere for a duration of the cooling of the infiltrated fiber preform to the ambient temperature,
• thereby forming a ceramic matrix composite having a surface configured for nodule removal.