US 11,920,245 B2
Method of forming an abrasive coating on a fan blade tip
Christopher W. Strock, Boothbay Harbor, ME (US); and Paul M. Lutjen, Kennebunkport, ME (US)
Assigned to RTX CORPORATION, Farmington, CT (US)
Filed by RTX CORPORATION, Farmington, CT (US)
Filed on Mar. 7, 2022, as Appl. No. 17/687,901.
Application 17/687,901 is a continuation of application No. 14/705,165, filed on May 6, 2015, granted, now 11,268,183.
Prior Publication US 2022/0195576 A1, Jun. 23, 2022
This patent is subject to a terminal disclaimer.
Int. Cl. C23C 4/08 (2016.01); C23C 4/06 (2016.01); C23C 4/12 (2016.01); C23C 4/123 (2016.01); C23C 4/134 (2016.01); C23C 4/18 (2006.01); F01D 5/28 (2006.01); F01D 11/12 (2006.01)
CPC C23C 4/08 (2013.01) [C23C 4/06 (2013.01); C23C 4/12 (2013.01); C23C 4/123 (2016.01); C23C 4/134 (2016.01); C23C 4/18 (2013.01); F01D 5/288 (2013.01); F01D 11/122 (2013.01); F05D 2230/312 (2013.01); F05D 2300/121 (2013.01); Y02T 50/60 (2013.01)] 18 Claims
OG exemplary drawing
 
1. A method of forming an abrasive coating on a rotating turbomachine component, the rotating turbomachine component comprising an airfoil section and a tip, the airfoil section and the tip having an aluminum or aluminum alloy substrate, the rotating turbomachine component designed to rotate within an abradable liner made of an abradable material, the method comprising the steps of:
providing a feedstock consisting of aluminum powder;
heating the aluminum powder until the aluminum powder is molten;
spraying the molten aluminum powder onto the substrate of the tip with a plasma spray gun to form a coating consisting of aluminum, wherein the plasma spray gun has an axis of rotation and an axis of powder injection, the plasma spray gun rotatable about its axis of rotation; and
depositing grit particles onto the coating while maintaining a temperature of the coating within a desired range by controlling deposition rate parameters;
wherein the deposition rate parameters include an aluminum powder feed rate of 20 g/min to 120 g/min, a traverse rate of the plasma spray gun of 1200 inches per minute to 20 inches per minute, the axis of powder injection oriented relative to a traverse direction, and a spray plume area;
wherein prior to or during spraying, rotation of the plasma spray gun about its axis of rotation changes the orientation of the axis of powder injection relative to the traverse direction of the plasma spray gun.
 
14. A method of forming an abrasive coating on a fan blade, the fan blade comprising an airfoil section and a tip, the airfoil section and tip having an aluminum or aluminum alloy substrate, the fan blade mounted to a hub and configured to rotate within a fan case assembly, the fan case assembly comprising an abradable liner made of an abradable material, the method comprising the steps of:
providing a feedstock consisting of aluminum powder;
heating the aluminum powder until the aluminum powder is molten;
spraying the molten aluminum powder onto the substrate of the fan blade tip with a plasma spray gun to form a matrix coating consisting of aluminum, wherein the plasma spray gun has an axis of rotation and an axis of powder injection, the plasma spray gun rotatable about its axis of rotation; and
depositing grit particles onto the matrix coating while maintaining a temperature of the matrix coating within a desired range by controlling deposition rate parameters;
wherein the deposition rate parameters include an aluminum powder feed rate of 20 g/min to 120 g/min, a traverse rate of the plasma spray gun of 1200 inches per minute to 20 inches per minute, the axis of powder injection oriented relative to a traverse direction, and a spray plume area;
wherein prior to or during spraying, rotation of the plasma spray gun about its axis of rotation changes the orientation of the axis of powder injection relative to the traverse direction of the plasma spray gun.
 
18. A method of forming an abrasive coating on a rotating turbomachine component, the rotating turbomachine component comprising an airfoil section and a tip, the airfoil section and the tip having an aluminum or aluminum alloy substrate, the rotating turbomachine component designed to rotate within an abradable liner made of an abradable material, the method comprising the steps of:
providing a feedstock consisting of aluminum powder;
heating the aluminum powder until the aluminum powder is molten;
spraying the molten aluminum powder onto the substrate of the tip with a plasma spray gun to form a coating consisting of aluminum, wherein the plasma spray gun has an axis of rotation and an axis of powder injection, the plasma spray gun rotatable about its axis of rotation; and
depositing grit particles onto the coating while maintaining a temperature of the coating within a desired range by controlling deposition rate parameters; wherein
the deposition rate parameters include an aluminum powder feed rate of 30 g/min to 60 g/min, a traverse rate of the plasma spray gun of 900 inches per minute to 500 inches per minute, the axis of powder injection oriented relative to a traverse direction, and a spray plume area;
wherein prior to or during spraying, rotation of the plasma spray gun about its axis of rotation changes the orientation of the axis of powder injection relative to the traverse direction of the plasma spray gun.