Method of forming cooling holes in ceramic matrix composite turbine components

摘要

A method for producing apertures (12) in hot section components of gas turbine engines made from ceramic matrix composites that have at least one oxidizable component is described. The method involves forming the apertures (12) using a laser beam controlled by parameters that ablate the ceramic matrix composite in the path of the beam, while simultaneously heating the matrix material (20), SiC or SiN, to a sufficient temperature to oxidize it to form a silica. Sufficient heat is supplied by the beam to melt the silica to cause it to flow. The melted silica is quickly solidified as recast silica (16) along the walls of the newly created aperture (12) before it has an opportunity to flow and form undesirable geometries. The wall (14) of the aperture (12) is formed of recast silica that is a smooth surface and that forms an oxidation barrier to inhibit any further oxidation of the underlying composite (10) as it is exposed to the high temperatures and oxidative, corrosive atmosphere of an operating gas turbine.