Chemistry: electrical and wave energy – Processes and products
Patent
1978-03-27
1978-12-05
Andrews, R. L.
Chemistry: electrical and wave energy
Processes and products
C25D 1108
Patent
active
041284615
ABSTRACT:
An improved anodizing process produces on aluminum and on alloys of aluminum a hard oxide film of greater thickness and better abrasion resistance then can be obtained in the conventional Sanford anodizing process which uses an organic substance sold under the trademark "Sanfran" as an additive to the electrolyte. In the improved process, the DC voltage employed in the conventional process is modulated by a sinusoidal AC voltage of standard industrial frequency and the modulation factor is not permitted to exceed 100% to prevent reversal of the current through the oxide film. The DC voltage is AC modulated during the entire term of the process. In an initial period of 1 to 2 minutes, the DC voltage is raised to about 10 volts and then is raised at a rate of about one half volt per minute to a level within the range of 14 to 19 volts. Upon reaching that level, the DC voltage is held constant for a dwell period of at least five minutes. The dwell period conduces to the production of an anodized coating of good industrial quality. Without the dwell period, the anodized coating produced is of inferior quality. Following the dwell period, the DC voltage is again gradually raised to cause the anodized film to increase in thickness.
REFERENCES:
patent: 2743221 (1956-04-01), Sanford
patent: 2897125 (1959-07-01), Franklin
patent: 2905600 (1959-09-01), Franklin
patent: 2977294 (1961-03-01), Franklin
patent: 3020213 (1962-02-01), Lupfer
Bessendorf Mikhael
Lerner Moisey
Morse James H.
Andrews R. L.
Sanford Process Corporation
LandOfFree
Aluminum hard anodizing process does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Aluminum hard anodizing process, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Aluminum hard anodizing process will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-285590