Method of anodizing a metal anode prepared from very fine metal powder
AssigneeKemet Electronics Corporation
InventorsJohn T. Kinard, Brian I. Melody
Life of this patent
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Abstract
Electrolytes containing water, at least one organic solvent, and at least one alkali metal phosphate salt can be used for anodizing valve metals prepared from metal powder having a surface area of least 0.35 m.sup.2 /g or 35,000 CV/g. The alkali metal phosphate salt should be relatively insoluble in the organic portion of the electrolyte, but highly soluble in a water solution of the organic solvent. The anodizing electrolytes have relatively high conductivity and are capable of being used at high anodizing currents. The anodic film produced by these electrolytes on valve metals is of substantially uniform thickness, has improved electrical parameters, and requires a shorter stabilization time at voltage.
Claims12
A method of anodizing a metal anode prepared from metal powder having a surface area of least 0.35 m.sup.2 /g or 35,000 CV/g, comprising anodizing the metal anode with an electrolyte comprising at least one alkali metal phosphate salt, water and at least one organic solvent wherein the alkali metal phosphate salt is insoluble in the organic solvent alone but soluble in a solution of the water and the organic solvent, wherein the total volume of organic solvent is above about 1 vol % and less than 50 vol. % of the total electrolytic solution volume, and wherein the anode is anodize at a temperature from about 60.degree. C. to about 100.degree. C.
Dependencies are inferred from the claim text.