Aluminium Anodizing and Its Advantages

Anodizing is not like electroplating and other organic coatings, it is unique to aluminum. It has greatly extended the applications of aluminum products and uses after it was developed in early 1930’s, where the metal or else not be utilized. The anodic finish is now available from aluminum finishing job shops all over the world and is quite inexpensive.

Anodizing will convert the surface of aluminum to an oxide. Though it would naturally form aluminum oxide on its surface, it will be a very thin film. It offers a thicker oxide coating several times thick if required. The rigidity of this aluminum oxide coating challenges that of diamond. Due to this anodizing improves abrasion resistance. It can also appreciably modify and improve the appearance of aluminum. By the usage of dyes and special procedures, the finisher can make aluminum look like stainless steel, pewter, copper, or brushed bronze. The process will improve corrosion resistance, particularly when the metal surface is in exposure to humid, industrial, and marine atmospheres. The electrical insulating property of the anodic finish finds its application when dielectric properties are significant for electrical components. This type of aluminum is simple to clean and it resists heat to the high temperature where the metal itself melts.

We can define anodizing as an electrochemical conversion process, and not an applied coating. The surface of the metal is converted to aluminum oxide as a result of reactions going on at the anode in an acidic solution. Oxide formation generally gets inward, towards the source of the fresh metal. The first formed oxide will remain in contact with the anodizing solution all through the process cycle; the last formed oxide is at the metal interface. The coating will be nearly 30-50 pct thicker than the original metal it replaces.

Structure of most coatings is predominantly porous. There will be a very slight non-porous barrier film at the interface. Process control starts with the quality of the metal, its precleaning and racking, and finally ends with unracking, possible "clean-up" and final inspection. The job shop finisher or captive department generally has the least control over a very important requirement for good anodizing that is the metal quality. Type of mill product, alloys, worth, temper and so on has significant effects on the appearance, oxide coating property and functional properties like abrasion and corrosion resistance of the end product.

The finisher must know about the metal that is to be treated. Some process changes should be made, and particular quality standards will be difficult to attain other than the proper alloy is being anodized. These can be formed in a range of chemical solutions, though only a handful is in industrial use. The advantage of anodizing aluminium is the potential of colored anodizing dye. These dye seeps into the microscopic pores of the anodized layer and colors it. This layer is then sealed and the color appears as part of the metal itself. This can be used for great artistic effect, making aluminium parts with strikingly tasteless colors to ornament your motor bike or, more topically, telescope.