Repair of a turbine engine surface containing crevices
View Patent ↗A composition and method for cleaning turbine engine components ( 10 ) during servicing. An embodiment of the invention includes a colloidal mixture or slurry ( 22 ) of nanoparticles. The slurry may be nontoxic and provide optimal cleaning of tiny surface-exposed crevices ( 18 ) of braze joints and components. When a colloidal mixture is in a polar solvent, the pH of the slurry is maintained at about 5 to 9 and at the isoelectric point of the nanoparticles to minimize or prevent agglomeration. When a colloidal mixture is in a nonpolar solvent, the pH of the slurry is maintained at about 5 to 9 and at the isoelectric point of the nanoparticles to minimize or prevent agglomeration by use of surfactant additives.
1. A method of repairing a turbine engine component, the method comprising:
applying a colloidal solution to a surface of a turbine engine component having a surface opening crevice, the colloidal solution comprising nanoparticles suspended in a solvent;
allowing the colloidal solution to penetrate the crevice and loosen a contaminant material disposed within a tip region of the crevice;
removing the colloidal solution and loosened contaminant material from the crevice and surface;
depositing a repair material onto the surface and into the crevice to penetrate the tip region of the crevice previously occupied by the contaminant material; and,
wherein the solvent comprises a non-polar solvent, and wherein the colloidal solution is characterized as:
(either nano silicon nitride or nano silicon carbide)+(either Decalin or Hexane)+polyvinyl chloride (particle D(50)), wherein particles of the colloidal solution are characterized by: particle D(50)=20 nm, 50 nm and/or 80 nma specific surface area=130 to 35 m 2 /g, and 5 to 25 volatile organic solids.
2. The method of claim 1 , further comprising agitating the colloidal solution against the contaminant material within the crevice with ultrasonic energy.
3. The method of claim 1 , wherein a hardness of a material of the nanoparticles is selected to be harder than a hardness of the contaminant material but softer than a hardness of a material of the surface.
4. The method of claim 1 , further comprising selecting the nanoparticles from the group consisting of ceramics, carbides, nitrides, and metalloids and combinations thereof, wherein said composition has a pH of about 5 to 9.
5. The method of claim 1 , further comprising selecting the nanoparticles to comprise two different materials.
6. The method of claim 1 , further comprising selecting the solution to exhibit a Zeta potential of at least +/−20 mV.
7. A method of repairing a turbine engine component, the method comprising:
applying a colloidal solution to a surface of a turbine engine component having a surface opening crevice, the colloidal solution comprising nanoparticles suspended in a solvent;
allowing the colloidal solution to penetrate the crevice and loosen a contaminant material disposed within a tip region of the crevice;
removing the colloidal solution and loosened contaminant material from the crevice and surface;
depositing a repair material onto the surface and into the crevice to penetrate the tip region of the crevice previously occupied by the contaminant material; and,
wherein the solvent comprises a non-polar solvent, and wherein the colloidal solution is characterized as:
nano silicon carbide+(either Decalin or Hexane)+polyvinyl chloride, wherein particles of the colloidal solution are characterized by: particle D(50)=20 nm, a specific surface area=130 to 35 m 2 /g, and 5 to 25 volatile organicsolids.
8. A method of repairing a turbine engine component, the method comprising:
applying a colloidal solution to a surface of a turbine engine component having a surface opening crevice, the colloidal solution comprising nanoparticles suspended in a solvent;
allowing the colloidal solution to penetrate the crevice and loosen a contaminant material disposed within a tip region of the crevice;
removing the colloidal solution and loosened contaminant material from the crevice and surface;
depositing a repair material onto the surface and into the crevice to penetrate the tip region of the crevice previously occupied by the contaminant material; and,
wherein the solvent comprises a non-polar solvent, and wherein the colloidal solution is characterized as:
nano silicon carbide+(either Decalin or Hexane)+polyvinyl chloride, wherein particles of the colloidal solution are characterized by: particle D(50)=50 nm, a specific surface area=130 to 35 m 2 /g, and 5 to 25 volatile organicsolids.
9. A method of repairing a turbine engine component, the method comprising:
applying a colloidal solution to a surface of a turbine engine component having a surface opening crevice, the colloidal solution comprising nanoparticles suspended in a solvent;
allowing the colloidal solution to penetrate the crevice and loosen a contaminant material disposed within a tip region of the crevice;
removing the colloidal solution and loosened contaminant material from the crevice and surface;
depositing a repair material onto the surface and into the crevice to penetrate the tip region of the crevice previously occupied by the contaminant material; and,
wherein the solvent comprises a non-polar solvent, and wherein the colloidal solution is characterized as:
nano silicon carbide+(either Decalin or Hexane)+polyvinyl chloride, wherein particles of the colloidal solution are characterized by: particle D(50)=80 nm, a specific surface area=130 to 35 m 2 /g, and 5 to 25 volatile organicsolids.