Method for repairing titanium alloy components

Abstract

A method for repairing a titanium alloy surface of a turbine component includes the step of cold gas-dynamic spraying a powder material comprising at least one titanium alloy directly on the titanium alloy surface. The method may further include the steps of hot isostatic pressing the cold gas-dynamic sprayed turbine component, and performing a separate heat treating step after the hot isostatic pressing. Thus, the cold gas-dynamic spray process and post-spray processing can be employed to effectively repair degraded areas on compressor turbine components.

1 . A method for repairing a titanium alloy surface of a turbine component, the method comprising the step of: 
 cold gas-dynamic spraying a powder material comprising at least one titanium alloy directly on the titanium alloy surface.    
   
   
       2 . The method of  claim 1 , wherein the powder material consists of at least one titanium alloy.  
   
   
       3 . The method of  claim 1 , wherein the powder material comprises at least one titanium alloy selected from the group consisting of near alpha titanium alloys, alpha-plus-beta titanium alloys, and near-beta titanium alloys.  
   
   
       4 . The method of  claim 1 , wherein the powder material comprises an alloy that is the same alloy that forms the titanium alloy surface.  
   
   
       5 . The method of  claim 1 , wherein the cold gas-dynamic spraying is performed in an atmosphere comprising an inert gas.  
   
   
       6 . The method of  claim 5 , wherein the inert gas comprises helium.  
   
   
       7 . The method of  claim 1 , further comprising the step of: 
 heating the turbine component at a temperature sufficiently high to consolidate the sprayed powder material.    
   
   
       8 . The method of  claim 1 , further comprising the step of: 
 performing a vacuum sintering on the turbine component after the cold gas-dynamic spraying step.    
   
   
       9 . The method of  claim 1 , further comprising the step of: 
 hot isostatic pressing the turbine component after the cold gas-dynamic spraying step.    
   
   
       10 . The method of  claim 9 , wherein the hot isostatic pressing step is performed 2 to 4 hours at temperatures of between about 1650 and about 1750° F. and at a pressure of at least 10 ksi.  
   
   
       11 . The method of  claim 1 , further comprising the step of: 
 heat treating the turbine component after the cold gas-dynamic spraying step, the heat treating comprising a first heating step performed for about one hour at a temperature between about 1725 and about 1775° F., followed by a second heating step performed for between about two and about eight hours at a temperature between about 900 and about 1100° F.    
   
   
       12 . The method of  claim 11 , wherein the titanium alloy surface being repaired comprises Ti-6Al-4V.  
   
   
       13 . The method of  claim 1 , further comprising the step of: 
 heat treating the turbine component after the cold gas-dynamic spraying step, the heat treating comprising a first heating step performed for about one hour at a temperature between about 1550 and about 1650° F., followed by a second heating step performed for between about four and about eight hours at a temperature between about 1075 and about 1125° F.    
   
   
       14 . The method of  claim 13 , wherein the titanium alloy surface being repaired comprises Ti-6Al-2Sn-4Zr-6Mo.  
   
   
       15 . The method of  claim 1 , further comprising the step of: 
 heat treating the turbine component after the cold gas-dynamic spraying step, the heat treating comprising a first heating step performed for about one hour at a temperature between about 1800 and about 1850° F., followed by a second heating step performed for between about four and about eight hours at a temperature between about 1050 and about 1100° F.    
   
   
       16 . The method of  claim 15 , wherein the titanium alloy surface being repaired comprises Ti-8Al-1Mo-1V.  
   
   
       17 . The method of  claim 1 , wherein turbine component comprises a compressor blade.  
   
   
       18 . The method of  claim 17 , wherein the compressor blade comprises a tip, and wherein the cold gas-dynamic spraying is performed on the tip.  
   
   
       19 . The method of  claim 17 , wherein the compressor blade comprises a leading edge, and wherein the cold gas-dynamic spraying is performed on the leading edge.  
   
   
       20 . The method of  claim 17 , wherein the compressor blade comprises a platform, and wherein the cold gas-dynamic spraying is performed on the platform.  
   
   
       21 . A method for repairing a titanium alloy surface of a turbine component, the method comprising the steps of: 
 cold gas-dynamic spraying a powder material comprising at least one titanium alloy directly on the titanium alloy surface;    hot isostatic pressing the cold gas-dynamic sprayed turbine component; and    heat treating the turbine component after the hot isostatic pressing.    
   
   
       22 . The method of  claim 21 , wherein the powder material consists of at least one titanium alloy.  
   
   
       23 . The method of  claim 21 , wherein the powder material comprises at least one titanium alloy selected from the group consisting of near alpha titanium alloys, alpha-plus-beta titanium alloys, and near-beta titanium alloys.  
   
   
       24 . The method of  claim 21 , wherein the powder material comprises an alloy that is the same alloy that forms the titanium alloy surface.  
   
   
       25 . The method of  claim 21 , wherein the cold gas-dynamic spraying is performed in an atmosphere comprising an inert gas.  
   
   
       26 . The method of  claim 25 , wherein the inert gas comprises helium.  
   
   
       27 . The method of  claim 21 , further comprising the step of: 
 before the hot isostatic pressing step, heating the turbine component at a temperature sufficiently high to consolidate the sprayed powder material.    
   
   
       28 . The method of  claim 21 , wherein the heat treating step comprises a first heating step performed for about one hour at a temperature between about 1725 and about 1775° F., followed by a second heating step performed for between about two and about eight hours at a temperature between about 900 and about 1100° F.  
   
   
       29 . The method of  claim 28 , wherein the titanium alloy surface being repaired comprises Ti-6Al-4V.  
   
   
       30 . The method of  claim 21 , wherein the heat treating step comprises a first heating step performed for about one hour at a temperature between about 1550 and about 1650° F., followed by a second heating step performed for between about four and about eight hours at a temperature between about 1075 and about 1125° F.  
   
   
       31 . The method of  claim 30 , wherein the titanium alloy surface being repaired comprises Ti-6Al-2Sn-4Zr-6Mo.  
   
   
       32 . The method of  claim 21 , wherein the heat treating step comprises a first heating step performed for about one hour at a temperature between about 1800 and about 1850° F., followed by a second heating step performed for between about four and about eight hours at a temperature between about 1050 and about 1100° F.  
   
   
       33 . The method of  claim 32 , wherein the titanium alloy surface being repaired comprises Ti-8Al-1Mo-1V.