Correcting defective kinetically sprayed surfaces
View Patent ↗Disclosed is a method for repairing defects in kinetically sprayed surfaces. The typical defects comprise isolated or connected conical shaped holes in the kinetic spray coating. The repair involves thermally spraying a molten material into the defective area to fill in the cone followed by continued kinetic spraying to complete the coating.
1. A method for repairing a defect in a kinetically sprayed surface comprising the steps of:
providing a kinetically sprayed surface having a thickness of at least 5 millimeters formed from particles maintained at a temperature below their melting temperature during kinetic spraying, the kinetically sprayed surface having a defect caused by said kinetic spraying; and
applying a repair coating to the defect by thermally spraying a molten material on the defect by a thermal spray process selected from the group consisting of a High Velocity Oxy-Fuel combustion thermal spray process, a wire arc thermal spray process, a vacuum plasma thermal spray process, a flame spray thermal process, or a radio frequency plasma thermal spray process thereby filling the defect and repairing the defect.
2. The method of claim 1 , wherein the molten material is formed from the same material as the kinetically sprayed surface.
3. The method of claim 1 , wherein the molten material has a different material composition from the kinetically sprayed surface.
4. The method of claim 1 , comprising the further step of applying an additional kinetically sprayed coating over the thermally sprayed once molten material.
5. The method of claim 1 , wherein the defect comprises at least one conical defect.
6. The method of claim 1 , wherein the molten material comprises at least one of a metal or an alloy.
7. The method of claim 6 , wherein the molten material comprises a nickel and copper alloy.
8. A method for repairing a defect in a kinetically sprayed surface comprising the steps of:
a) providing a kinetically sprayed surface having a thickness of at least 5 millimeters formed from particles maintained at a temperature below their melting temperature during kinetic spraying, the kinetically sprayed surface having a defect caused by said kinetic spraying;
b) applying a repair coating to the defect by thermally spraying a molten material on the defect by a thermal spray process selected from the group consisting of a High Velocity Oxy-Fuel combustion thermal spray process, a wire arc thermal spray process, a vacuum plasma thermal spray process, a flame spray thermal process, or a radio frequency plasma thermal spray process thereby filling the defect and repairing the defect; and
c) applying an additional kinetically sprayed surface over the repaired defect.
9. The method of claim 8 , wherein step b) comprises using a molten material formed from the same material as the kinetically sprayed surface.
10. The method of claim 8 , wherein step b) comprises using a molten material having a different material composition from the kinetically sprayed surface.
11. The method of claim 8 , wherein step a) comprises providing a defect comprising at least one conical defect.
12. The method of claim 8 , wherein step b) comprises using a molten material comprising at least one of a metal or an alloy.
13. The method of claim 12 , wherein the molten material comprises a nickel and copper alloy.