Claims
- 1. A coated metal or coated ceramic part which exhibits improved salt corrosion and oxidation resistance, which part is coated with a cured coating composition or a cured binder which comprises phosphate ions and ions of the group of chromate or molybdate ions, and an atomized aluminum powder having an average particle size (as expressed in terms of the median equivalent spherical diameter (ESD), that is greater than at least 15 .mu.m, and having a size distribution such that at least about 5% of the particles by weight are retained on a 325 mesh screen.
- 2. The metal part of claim 1 which is a thick multilayer coating, each layer being from about 0.003 to about 0.030 inch thick.
- 3. The coated part of claim 1 wherein the particle size distribution of the aluminum has a single maximum, due to the presence of one or more grades of atomized powder, each having an ESD greater than 15 .mu.m.
- 4. The coated part of claim 1 wherein the particle size distribution curve of the aluminum has a particle size distribution curve, which curve has two peak frequencies which are attributable to the presence of a mixture of larger particle size powder which has an average particle size greater than 15 .mu.m and in which the size distribution is such that at least about 5% by weight of the particles are greater than 44 microns, and of at most 50 weight percent a mixture of smaller particle size powder, the two powders being in such ratio that the ESD of the smaller to the larger powder is less than 0.5, the average particle size ofthe powders being expressed in terms of the median eqivalent spherical diameter, ESD.
- 5. The coated part of claim 1 wherein the weight percentage of the powder of smaller particle size is between 15 and 25 .mu.m.
- 6. The coated part of claim 1 wherein the ratio of the ESD of the powder of smaller particle size to that of the larger particle size powder is less than 0.12.
- 7. The coated part of claim 1 wherein the ratio of the ESD's of powders of smaller and larger particle size is less than 0.12 and the weight percentage of the powder of smaller particle size is between 15 and 25.
- 8. The coated part of claim 1 wherein the particle size distribution curve has two distinct peak frequencies attributable to the presence of a powder with an ESD particle size greater than 15 .mu.m and at most 50 weight percent of a small particle size powder, selected such that the ratio of the ESD of the later powder to that of the former powder is less than 0.5.
- 9. The metal part of claim 1 which is diesel engine turbocharger inlet housing.
- 10. The metal part of claim 1 which is an aircraft engine case.
- 11. The metal part of claim 1 which is a compressor case of an aircraft turbine engine.
- 12. The metal part of claim 1 which is a compressor blade or an aircraft turbine engine.
- 13. The metal part of claim 1 which has a ferrous surface.
- 14. The metal part of claim 1 the coating of which is at least about 0.100 inch thick.
- 15. The metal part of claim 1 which is abradable.
- 16. The coated part of claim 1 wherein the weight percentage of the powder of smaller particle size is between 15 and 25, the ratio of ESD's of the powder of smaller and larger particles size is less than 0.12 and the radius of the small particles is not greater than 0.22 times the radius of the larger particles.
- 17. The coated part of claim 16 wherein the average diameter of the smaller powder is at least about one-half of the average particle size of the particles of the larger particles of the powder.
- 18. The coated part of claim 17 wherein the relative weight ratio of the larger to the smaller particles of the powders is about 4 to 1.
- 19. The coated part of claim 18 wherein the average particle size of the smaller particles of the powder is at least about one-tenth of the average particle size of the larger particles of the powder.
- 20. The metal part of claim 1 wherein the aluminum powders are spherical powders.
- 21. The metal part of claim 20 wherein the spherical aluminum powders are air-atomized powders.
Parent Case Info
This is a division, of application Ser. No. 566,514, filed Dec. 29, 1983, now U.S. Pat. No. 4,617,056.
US Referenced Citations (6)
Divisions (1)
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Number |
Date |
Country |
Parent |
566514 |
Dec 1983 |
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