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United States Patent 6,441,341
Steibel ,   et al. August 27, 2002

Method of forming cooling holes in a ceramic matrix composite turbine components

Abstract

A method for producing apertures in hot section components of gas turbine engines made from ceramic matrix composites that have at least one oxidizable component. The method involves forming the apertures 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, 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 along the walls of the newly created aperture before it has an opportunity to flow and form undesirable geometries. The wall of the aperture 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 as it is exposed to the high temperatures and oxidative, corrosive atmosphere of an operating gas turbine.


Inventors: Steibel; James Dale (Hamilton, OH); Edmondson; Wayne Garcia (Xenia, OH); Scheidt; Wilbur Douglas (Cincinnati, OH)
Assignee: General Electric Company (Schenectady, NY)
Appl. No.: 595866
Filed: June 16, 2000

Current U.S. Class: 219/121.71; 219/121.66
Intern'l Class: B23K 026/18
Field of Search: 219/121.71,121.7,121.83,121.85,121.65,121.66 29/889.721,889.72,889.71


References Cited

U.S. Patent Documents
4276331Jun., 1981Bothwell428/36.
4642271Feb., 1987Rice428/698.
4738902Apr., 1988Prewo et al.428/697.
4762464Aug., 1988Vertz et al.416/97.
4808785Feb., 1989Vertz et al.219/69.
4837230Jun., 1989Chen et al.501/88.
4873414Oct., 1989Ma et al.219/121.
5140127Aug., 1992Stroud et al.219/121.
5147587Sep., 1992Marcus et al.264/22.
5222617Jun., 1993Gregory et al.219/121.
5465780Nov., 1995Muntner et al.164/516.
5683600Nov., 1997Kelley et al.219/121.
5747769May., 1998Rockstroh et al.
5773790Jun., 1998Moore et al.
5837964Nov., 1998Emer et al.219/121.
5853653Dec., 1998Donato et al.264/625.
5879803Mar., 1999Masaki et al.428/378.
5914060Jun., 1999Flis et al.
6054673Apr., 2000Chen219/121.
6339208Jan., 2002Rockstroh et al.
Foreign Patent Documents
488402Jun., 1992EP.
770448May., 1997EP.
826457Mar., 1998EP.

Primary Examiner: Dunn; Tom
Assistant Examiner: Johnson; Jonathan
Attorney, Agent or Firm: Narcisco; David L. McNees Wallace & Nurick L., Maria; Carmen Santa

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