Cold spraying method for coating compressor and turbine blade tips with abrasive materials

Abstract

A method for coating compressor or turbine blade tips of a bladed disk with abrasive particles includes installing the blades onto a disk, and then cold gas-dynamic spraying the abrasive particles onto the blade tips while the blades are installed in the disk. According to another embodiment, a method for coating compressor and turbine blade tips of a bladed wheel with abrasive particles includes grinding the blade tips to bring the bladed wheel to a predetermined diameter. Then, surfaces of the bladed wheel not requiring coating are masked. After masking the surface not to be coated, the abrasive particles are cold gas-dynamic sprayed onto the blade tips. For both embodiments, an oxidation resistant layer may be cold gas-dynamic sprayed on the blade tips prior to spraying the abrasive particles.

1 . A method for coating compressor or turbine blade tips of a bladed disk with abrasive particles, comprising the steps of:
 installing the blades onto a disk; and   cold gas-dynamic spraying the abrasive particles onto the blade tips while the blades are installed in the disk.   
   
   
       2 . The method according to  claim 1 , further comprising the step of:
 grinding the blade tips, after installing the blades onto the disk and before cold gas-dynamic spraying the abrasive particles onto the blade tips, until the bladed disk is brought to a predetermined diameter.   
   
   
       3 . The method according to  claim 1 , further comprising the step of:
 masking surfaces of the bladed disk not requiring the abrasive coating before performing the cold gas-dynamic spraying step.   
   
   
       4 . The method according to  claim 1 , wherein the method excludes any grinding of the blade tips after cold gas-dynamic spraying the abrasive particles. 
   
   
       5 . The method according to  claim 1 , further comprising the step of:
 heat treating the blade tips after cold gas-dynamic spraying the abrasive particles.   
   
   
       6 . The method according to  claim 1 , wherein the method excludes removing of the turbine blades from the disk after cold gas-dynamic spraying the abrasive particles. 
   
   
       7 . The method according to  claim 1 , wherein the step of cold gas-dynamic spraying the abrasive particles onto blade tips comprises spraying abrasive particles selected from the group consisting of cubic boron nitride, diamond, silicon carbide, yttrium aluminum garnet, and cubic zirconia. 
   
   
       8 . The method according to  claim 7 , wherein the step of cold gas-dynamic spraying the abrasive particles onto the blade tips comprises spraying cubic boron nitride particles. 
   
   
       9 . The method according to  claim 7 , wherein the step of cold gas-dynamic spraying the abrasive particles onto the blade tips comprises spraying particles having an average diameter ranging between 25 and 100 microns. 
   
   
       10 . The method according to  claim 8 , further comprising the step of:
 forming a MCrAlY oxidation resistant layer on the blade tips prior to cold gas-dynamic spraying the abrasive particles.   
   
   
       11  The method according to  claim 10 , wherein the MCrAlY oxidation resistant layer is formed using a cold gas-dynamic spraying process. 
   
   
       12 . The method according to  claim 1 , wherein the step of cold gas-dynamic spraying the abrasive particles onto the turbine blades comprises partially embedding the particles into the tips of the blades. 
   
   
       13 . The method according to  claim 1 , wherein the step of cold gas-dynamic spraying the abrasive particles onto the turbine blades comprises spraying only tip portions of the blades with the abrasive particles. 
   
   
       14 . The method according to  claim 1 , wherein the step of cold gas-dynamic spraying the abrasive particles onto the turbine blades comprises the step of spraying the abrasive particles while spinning the bladed disk. 
   
   
       15 . The method according to  claim 14 , wherein the step of spraying the abrasive particles while spinning the bladed disk comprises constantly spraying the abrasive particles until each blade tip is coated with the abrasive particles. 
   
   
       16 . The method according to  claim 14 , spraying the abrasive particles while spinning the bladed disk comprises intermittently halting the spinning when each individual blade reaches a position to receive a coating of abrasive materials. 
   
   
       17 . A method for coating compressor and turbine blade tips of an integrally bladed wheel with abrasive particles, comprising the steps of:
 grinding the blade tips to bring the bladed wheel to a predetermined diameter;   masking surfaces of the bladed wheel not requiring coating; and   cold gas-dynamic spraying the abrasive particles onto the blade tips.   
   
   
       18 . The method according to  claim 17 , wherein the bladed wheel is selected from the group consisting of an integral axial compressor wheel, an impeller, and an integral turbine wheel. 
   
   
       19 . The method according to  claim 17 , wherein the step of cold gas-dynamic spraying the abrasive particles onto the turbine blades comprises the step of spraying the abrasive particles while spinning the bladed disk. 
   
   
       20 . The method according to  claim 19 , wherein the step of spraying the abrasive particles while spinning the bladed disk comprises constantly spraying the abrasive particles until each blade tip is coated with the abrasive particles. 
   
   
       21 . The method according to  claim 19 , wherein the step of spraying the abrasive particles while spinning the bladed disk comprises intermittently halting the spinning when each individual blade reaches a position to receive a coating of abrasive materials.