Method for modifying stoichiometric NiA1 coatings applied to turbine airfoils by thermal processes
A method for producing a turbine airfoil that is coated with a beta phase, high aluminum content coating, such as substantially stoichiometric NiAl, and which has a surface finish suitable for application of a ceramic topcoat. The method involves impacting the coating with preselected particles of a...
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| Main Authors | , |
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| Format | Patent |
| Language | English |
| Published |
19.12.2002
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| Online Access | Get full text |
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| Summary: | A method for producing a turbine airfoil that is coated with a beta phase, high aluminum content coating, such as substantially stoichiometric NiAl, and which has a surface finish suitable for application of a ceramic topcoat. The method involves impacting the coating with preselected particles of a preselected size so that the brittle coating is not adversely affected by chipping or breakage. The impacting produces a surface finish of 120 micro-inches or better so that a ceramic thermal barrier layer can be applied over the coating. The preferred method of improving the surface finish utilizes steel balls having a diameter of about 0.033″ and a peening intensity of no greater than about 6A. |
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