Cold spray method of applying aluminum seal strips

Abstract

A method for applying a seal strip to a surface of a turbine component by accelerating solid particles to a velocity sufficient to cause the solid particles to plastically deform and bond to the surface and each other when impacted on the surface, and impacting the solid particles on the surface so as to cause the solid particles to deform and bond to the surface and each other to form the seal strip on the surface.

1 . A method for applying a seal strip to a component comprising:
 providing the component having a surface;   accelerating solid particles to a velocity sufficient to cause the solid particles to plastically deform and bond to the surface and each other when impacted on the surface; and   impacting the solid particles on the surface so as to cause the solid particles to deform and bond to the surface and each other to form the seal strip on the surface.   
     
     
         2 . The method of  claim 1 , wherein the solid particles comprise aluminum. 
     
     
         3 . The method of  claim 1 , wherein the solid particles comprise a powdered metal. 
     
     
         4 . The method of  claim 1 , wherein the component comprises a turbine bucket having a dovetail, and the surface is located on the dovetail. 
     
     
         5 . The method of  claim 1 , wherein accelerating the solid particles uses a high-pressure gas. 
     
     
         6 . The method of  claim 5 , wherein the high-pressure gas comprises helium. 
     
     
         7 . The method of  claim 5 , wherein the high-pressure gas comprises air. 
     
     
         8 . The method of  claim 1 , wherein the velocity is greater than about 350 m/sec. 
     
     
         9 . The method of  claim 1 , further comprising dispersing the solid particles in a carrier gas before accelerating the solid particles. 
     
     
         10 . A method for applying a seal strip to a component comprising:
 providing the component having a surface;   providing a spray coating apparatus comprising
 a deposition nozzle; 
 a powder fluidizing unit; and 
 a pressurized gas source; 
 wherein the powder fluidizing unit is configured to disperse solid particles into a carrier gas and the pressurized gas source provides sufficient pressure to accelerate the solid particles dispersed in the carrier gas through the deposition nozzle at a velocity sufficient to cause the solid particles to plastically deform and bond to the surface and each other when impacted on the surface; 
   accelerating the solid particles through the deposition nozzle; and   impacting the solid particles on the surface so as to cause the solid particles to deform and bond to the surface and each other to form the seal strip on the surface.   
     
     
         11 . The method of  claim 10 , wherein the solid particles comprise aluminum. 
     
     
         12 . The method of  claim 10 , wherein the solid particles comprise a powdered metal. 
     
     
         13 . The method of  claim 10 , wherein the component comprises a turbine bucket having a dovetail, and the surface is located on the dovetail. 
     
     
         14 . The method of  claim 10 , wherein the solid particles are accelerated using a high-pressure gas. 
     
     
         15 . The method of  claim 14 , wherein the high-pressure gas comprises helium. 
     
     
         16 . The method of  claim 14 , wherein the high-pressure gas comprises air. 
     
     
         17 . The method of  claim 10 , wherein the velocity is greater than about 350 m/sec. 
     
     
         18 . The method of  claim 10 , wherein the deposition nozzle is attached to a robotic arm. 
     
     
         19 . The method of  claim 10 , wherein the surface of the component is unmasked. 
     
     
         20 . The method of  claim 18 , wherein the robotic arm is automatically controlled to deposit the seal strip on the surface of the component.