Methods and materials for forming in-situ cavities for silicon-based ceramic matrix composite components

A method of forming a ceramic matrix composite component with cooling features, comprising:

• forming a preform tape;
• laying up said preform tape to a desired shape;
• placing a high-temperature resistant fugitive material in the form of an insert of preselected geometry in said preform tape to form a lay-up of the ceramic matrix composite component;
• compacting said lay-up to form a preform;
• pyrolyzing said preform by burning out said preform to form a porous preform;
• melt infiltrating said porous preform with molten silicon to form said ceramic matrix composite component;
• wherein the method comprises forming said cooling features, by one or both of reducing said high temperature resistant fugitive material or removing said insert, during or following one of said pyrolyzing or said melt infiltrating.