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| About Anodizing |
| Anodic Coatings on Aluminum |
| Anodizing converts the surface of aluminum to an oxide. While the aluminum naturally forms aluminum oxide on its surface, this is a very thin film. anodizing provides a much thicker oxide coating ( several mils thick if required). Anodizing uses simple water-based chemicals that can be treated easily and that release no harmful by-products. The liquid by-products are recycled and returned to the process. Solid by-products can be isolated and diverted for use in the manufacture of alum, baking powder, cosmetics, newsprint, fertilizer and waer purification systems. |
| Anodizing is an electrochemical conversion process, not an applied coating. The surface of the aluminum metal is converted to aluminum oxide as a result of the reactions occurring at the anode in an acidic solution. The thickness and properties of the anodic coating will vary with alloy, electrolyte composition, anodizing process employed and cycle time. |
| Anodizing (with suitable pre-finishing) can appreciable alter and improve the appearance of aluminum. By using dyes and special anodizing procedures aluminum can look like pewter, stainless steel, copper, or brushed bronze. Anodizing improves corrision resistance, especially when the metal surface is exposed toindustrial, humid and marine atmospheres. The electrical insulating properties of the anodic finish find application when dielectric properties are important for electrical components. |
| A. AMS-2468 - Hardcoat B. AMS-2469 - Hardcoat. C. AMS - 2470 - Chromic D. AMS - 2471 - Sulfuric Clear E. AMS - 2472 - Sulfuric Colored F. Mil - A - 8625 - Type I Classes 1 ( clear) and 2 ( colored) - Chromic G.Mil - A - 8625 Type II Classes 1 ( clear) and 2 ( colored) - Sulfuric H. Mil - A - 8625 Type III Hardcoat |
| I. INTRODUCTION |
| II. FORMATION OF ANODIC COATINGS |
| III. GENERAL PROPERTIES OF ADONIC COATINGS |
| IV. APPLICABLE STANDARDS |
| Oxide formation proceeds inward, towards the source of fresh metal. The first form oxide remains in contact with the anodizing soulution throughout the process cycle; the last formed oxide is the metal surface. |
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