Patent Application
20110047777
This disclosure relates to an abrasive finish mask. The disclosure also relates to a method of abrasively polishing a component.
Abrasive finishing or polishing is used to round off sharp edges and remove material from components. Various engine components in the aerospace industry, such as stator clusters, utilize abrasive polishing to improve the surface finish of the component. Typically, portions of the component must be masked to prevent undesired polishing or material removal on those portions to maintain desired dimensions. One method of component polishing includes depositing the masked component into a slurry containing abrasive media. The slurry is agitated in a manner that causes the abrasive media to remove material from unmasked areas of the component. Masked areas of the component are protected from the abrasive media and remain dimensionally unchanged.
Current masking techniques are labor and time intensive and, for example, apply a masking material that is adhered to the component. Quite often other processes are needed to clean the polished component to remove remnants left from the masking process, which is undesirable. Occasionally, process incidental damage may result when the masking is removed from the component.
A mask for a component is disclosed that includes a flexible gasket having a first cavity with a shape configured to generally correspond to at least a portion of a contour of a component masking area. The flexible gasket has an outer surface. A backer, which is more rigid than the flexible gasket, includes a second cavity having an inner surface that generally corresponds to the outer surface. The inner surface is configured to be engageable with the outer surface in an installed condition and deflect the outer surface away from the inner surface to compress the flexible gasket between the inner surface and the portion.
A method of masking a component includes installing a flexible gasket over a portion of a component masking area leaving an unmasked area exposed. A backer is installed over the flexible gasket to compress the flexible gasket between the backer and the portion. The flexible gasket and the backer are secured to the component to provide an assembly. The assembly is deposited into a slurry with an abrasive media to polish the unmasked area, in one example. The flexible gasket and backer prevent abrasive media from reaching the masked area. The flexible gasket and backer can be removed from the component and reused on other similarly shaped components.
The example component 10 includes inner and outer ends 18, 20 in the masking area 12. Radially extending vanes 16 interconnect the inner and outer ends 18, 20 in the unmasked area 14. The vanes 16 are polished during the abrasive polishing process to improve the aerodynamic surface finish of the vane 16, which are arranged in the flow path of a gas turbine engine.
A reusable mask 13 is removably installed onto each of the inner and outer ends 18, 20 to cover the masking area 12. The masks 13 are secured about the component 10 to provide an assembly 15 that can be deposited into a polishing machine 48 having abrasive media 52 (
The flexible gasket 22 includes a cavity 26 that receives the inner end 18. The cavity 26 includes a locating feature 28 that cooperates with a complementary feature on the inner end 18, such as a slot 30 in an installed position. An opening 31 adjoins the cavity 26.
Referring to
In one example, the inner and outer surfaces 34, 36 are canted at an approximately 10° angle toward the opening 31 in an uninstalled position (
Another backer 25 and flexible gasket is installed onto the outer end 20 in a manner similar to that described above relative to the inner end 18.
Referring to
The assembly 15 is deposited into a polishing machine 48. The polishing machine 48 includes a tank 49 filled with a slurry 50 having abrasive media 52. A vibratory device 54 agitates the slurry 50 causing the abrasive media 52 to remove and polish material from the unmasked area 14. The masks 13 at the ends 18, 20 of the component 10 seal out the abrasive media 52 from the masking area 12 on the component 10. The zip ties are cut to remove the flexible gaskets 22 and backers 24, 25 from the component 10. The flexible gaskets 22 and backers 24, 25 can be reused with other similarly shaped components.
Although example embodiments have been disclosed, a worker of ordinary skill in this art would recognize that certain modifications would come within the scope of the claims. For that reason, the following claims should be studied to determine their true scope and content.
