Additive-assisted cerium-based electrolytic coating process for corrosion protection of aluminum alloys
AssigneeThe Curators of the University of Missouri
InventorsJames O. Stoffer, Thomas J. O'Keefe, Eric L. Morris, Scott Hayes, Paul Yu, Alex Williams, Xuan Lin
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Abstract
The corrosion resistance of an aluminum or aluminum alloy component is enhanced by immersing an aluminum alloy to act as a cathode and an oxygen-evolving anode in an electrolyte comprising water, cerium ions, and an additive selected from among animal gelatin, derivatives of animal gelatin, and amino acids, then passing an electrical current through the electrolyte to deposit a cerium-based coating onto the aluminum-based component.
Claims29
A process for enhancing the corrosion resistance of an aluminum-based component comprising:
- immersing the aluminum-based component as a cathode, and an oxygen-evolving anode, in an electrolyte comprising water, cerium ions, and an additive selected from the group consisting of animal gelatin, derivatives of animal gelatin, and amino acids;
- and
- passing an electrical current through the electrolyte to deposit a cerium-based coating onto the aluminum-based component.
A process for enhancing the corrosion resistance of an aluminum-based component comprising:
- immersing the aluminum-based component and an oxygen-evolving anode in an electrolyte comprising a source of cerium ions, water, hydrogen peroxide, and an additive selected from the group consisting of animal gelatin, derivatives of animal gelatin, and amino acids;
- and
- passing an electrical current through the electrolyte to facilitate cathodic precipitation under conditions characterized by a current density of at least about 1 mAmp/cm2 and of no more than about 50 mAmps/cm2 to deposit a cerium-based coating onto the aluminum-based component, said coating having a thickness of at least about 0.1 microns;
- wherein the electrolyte has the following characteristics:
- a pH of between about 1 and about 4.5;
- a hydrogen peroxide concentration between about 1 vol % and about 20 vol %;
- a cerium ion concentration between about 0.01 mole per liter and about 1 mole per liter;
- a concentration of said additive selected from the group consisting of animal gelatin, derivatives of animal gelatin, and amino acids of between about 0.01 wt % and about 1 wt % of the electrolyte.
Dependencies are inferred from the claim text.