Aluminum is used in industry because it has a good strength-to-weight ratio. Aluminum also has decent corrosion resistance because it has a very strong affinity for oxygen, which forms a thin and tenacious oxide layer on its surface and protects the underlying metal from further oxidation. However, aluminum isn’t a very hard metal and can be scratched fairly easily. Ceramics (oxides) are much harder than most metals, so to improve the scratch resistance of aluminum, “anodizing” is used to thicken the oxide layer. The thicker oxide layer also improves the metals corrosion resistance.
What is the anodizing Process?
Metals are anodized by placing them in an acidic bath, often sulfuric acid, and the acid corrodes the metal resulting in a very thick oxide (ceramic) layer on the metal surface. This oxide layer is porous, and can be up to 50 µm thick (2 mils) and appear as different colors depending on its thickness. Aluminum oxide is typically gray or black in color. The porous surface oxide layer has to be “sealed” to complete the process, and this is accomplished by submerging the sample in warm water which hydrates the oxide and shrinks the pores. Putting dyes in the water during the sealing process allows the as the dye to permeate the oxide layer, this is how colorful products are created.
Aluminum details :
Alloy 5052 Temper H38
Chemical Composition Limits (%)
Magnesium gives this alloy its enhanced corrosion resistance, work ability, strength, and weld ability. Typical uses include aircraft fuel tanks, electronic mounting plates and panels, fan blades, refrigeration liners, storm shutters, and utensils.
Mechanical Property Limits
Anodized Aluminum advantage:
Protects satellites from the harsh environment of space.
Used in one of the world's tallest buildings --- the Sears Tower in Chicago, Illinois.
Provides attractive, minimum-maintenance, highly durable exteriors, roofs, curtain walls, ceilings, floors, escalators, lobbies and staircases in skyscrapers and commercial buildings throughout the world.
Revolutionized the construction of computer hardware, exhibit displays for trade shows, scientific instruments, and a constantly expanding array of home appliances, consumer products, and building materials.
Considered environmentally safe, producing few, if any, harmful effects on land, air, or water.