Abrasive blade tip treatment

Patent metadata

Field	Value
Publication number	US-2015337671-A1
Application number	US-201514706369-A
Country	US
Kind code	A1
Filing date	May 7, 2015
Priority date	May 23, 2014
Publication date	Nov 26, 2015
Grant date	—

Abstract

An abrasive coating for a metal airfoil tip in a gas turbine engine may include a plurality of grit particles coated with a braze alloy material and configured for attachment to the airfoil tip. The braze alloy may be a nickel base, cobalt base or iron base braze alloy or mixtures thereof, or a titanium base braze alloy.

First claim

1 . An abrasive coating for a metal airfoil tip in a gas turbine engine, the abrasive coating comprising:
an abrasive layer having a plurality of grit particles partially coated with a braze alloy and configured for attachment to the airfoil tip.

2 . The abrasive coating of claim 1 , wherein the grit particles are selected from the group consisting of cubic boron nitride (CBN), zirconia, alumina, silicon carbide, and diamond.

3 . The abrasive coating of claim 2 , wherein the grit particles comprise CBN.

4 . The abrasive coating of claim 1 , wherein the braze alloy comprises a nickel base, cobalt base, or iron base braze alloy or mixtures thereof, or a titanium base braze alloy.

5 . The abrasive coating of claim 4 wherein the braze alloy wets the grit particles and the airfoil tip.

6 . The abrasive coating of claim 1 , wherein the braze alloy layer thickness is less than the mean grit particle diameter.

7 . The abrasive coating of claim 1 , wherein the grit particles have a particle size ranging from about 20 microns to about 200 microns.

8 . The abrasive coating of claim 7 , wherein the grit particles have a particle size ranging from about 50 microns to about 150 microns.

9 . An assembly for a gas turbine engine, the assembly comprising:
at least one abrasive layer having a plurality of grit particles partially coated with a braze alloy; and an airfoil having a tip, wherein the braze alloy is substantially disposed between at least a set of the plurality of grit particles and the tip.

10 . The assembly of claim 9 , wherein the airfoil comprises a nickel base, a cobalt base, an iron base superalloy or mixtures thereof or a titanium alloy.

11 . The assembly of claim 9 , wherein the grit particles are selected from the group consisting of cubic boron nitride (CBN), zirconia, alumina, silicon carbide, and diamond.

12 . The assembly of claim 9 , wherein the braze alloy comprises a nickel base, cobalt base, or iron base braze alloy or mixtures thereof, or a titanium base braze alloy.

13 . The assembly of claim 12 , wherein the braze alloy wets the set of grit particles and the airfoil tip.

14 . The abrasive coating of claim 9 , wherein the braze alloy layer thickness is less than the mean grit particle diameter.

15 . A method of forming an abrasive layer on a metal airfoil tip in a gas turbine engine comprising:
depositing a plurality of grit particles coated with a braze alloy on the metal airfoil tip; and heating preselected regions of the tip after the depositing to produce a patterned layer of grit particles attached to the airfoil tip.

16 . The method of claim 15 , wherein the grit particles are selected from the group consisting of cubic boron nitride (CBN), zirconia, alumina, silicon carbide, and diamond.

17 . The method of claim 15 , wherein the braze alloy comprises a nickel base, cobalt base, or iron base braze alloy or mixtures thereof, or a titanium base braze alloy.

18 . The method of claim 15 , wherein heating preselected regions of the tip comprises directing an energy beam to melt the braze alloy to produce the patterned layer of grit particles attached to the airfoil tip.

19 . The method of claim 18 , wherein the energy beam is a laser or electron beam.

20 . The method of claim 15 , wherein the patterned layer of grit particles is attached to the airfoil tip by a braze alloy layer after the molten braze alloy solidifies.

Assignees

• United Technologies Corp

Inventors

• Strock Christopher W
• Guo Changsheng

Classifications

• B23K1/0018 Primary

  Brazing of turbine parts · CPC title

• B22F10/28

  Powder bed fusion, e.g. selective laser melting [SLM] or electron beam melting [EBM] · CPC title

• B05D5/00

  Processes for applying liquids or other fluent materials to surfaces to obtain special surface effects, finishes or structures · CPC title

• F01D5/288 Primary

  Protective coatings for blades · CPC title

• B05D3/0254

  After-treatment · CPC title