Methods of forming ceramic matrix composite structures

A method of forming a ceramic matrix composite structure, comprising:

• infiltrating ceramic fiber preforms with at least one of an oxide-based pre-ceramic matrix slurry and a non-oxide-based pre-ceramic matrix slurry to form prepregged composite materials;
• placing the prepregged composite materials in continuous, edge to edge, contact over a surface of a tool using an advanced fiber placement apparatus to form at least one layer of the prepregged composite materials;
• subjecting the at least one layer of the prepregged composite materials to a curing process to form a substantially cured composite material structure;
• and
• subjecting the substantially cured composite material structure to a densification process.

A method of forming a ceramic matrix composite structure, comprising:

• forming at least one prepregged composite material comprising at least one tow of ceramic fibers impregnated with a pre-ceramic matrix slurry;
• placing the at least one prepregged composite material over at least one surface of a tool having an irregular three-dimensional shape using an advanced fiber placement apparatus to form an at least partially uncured composite material structure;
• curing the at least partially uncured composite material structure to form a cured composite material structure;
• and
• exposing the cured composite material structure to a sintering process or a pyrolysis process.

A method of forming a ceramic matrix composite structure, comprising:

• forming prepregged composite materials each independently comprising a ceramic fiber preform and a pre-ceramic matrix slurry over and around ceramic fibers of the ceramic fiber preform;
• forming layers of the prepregged composite materials over at least one contoured surface of a tool using an advanced fiber placement apparatus, at least one of the layers of the prepregged composite materials oriented in a direction about 45 degrees offset from a direction of another of the layers of the prepregged composite materials and about 90 degrees offset from a direction of yet another of the layers of the prepregged composite materials;
• and
• exposing the layers of the prepregged composite materials at least to elevated temperatures to cure and densify the layers of the prepregged composite materials.