Aluminium and light alloys

Also called anodizing, anode oxidation is an electrochemical process widely used to improve the surface properties of metals, especially aluminum, but also titanium and other materials. This process creates an oxide layer on the metal surface, which offers numerous advantages including improved corrosion resistance, better surface hardness and a more aesthetically pleasing finish.

Anodic oxidation is a highly effective surface treatment technique which therefore offers a combination of protection, durability and aesthetics. Its application extends across many sectors, demonstrating its versatility and importance. With the continuous development of innovative technologies and solutions, anodic oxidation remains the preferred choice to improve the performance and appearance of a wide range of metal components, meeting the durability and quality requirements of the modern market.

Blue Water Technology  has a long experience in the design and construction of plants for water purification and treatment. In the field of aluminium and light alloys, plants and machines are installed for the treatment of waste water from anodic oxidation plants.

The anodic oxidation process

Fundamental principle

• Description: Anodic oxidation is a process in which the metal to be treated (anode) is immersed in an electrolytic solution and connected to an electrical current source. During the process, the anode undergoes an oxidation which generates a layer of oxide on the metal surface.
• Electrochemical reaction: the electric current induces an electrochemical reaction which transforms part of the surface metal into metallic oxide, creating a protective and decorative layer.

Process steps

• Surface preparation: Before anodizing, the metal must be cleaned and prepared to remove existing impurities and oxides. This step may include washing, degreasing and pickling.
• Immersion and current application: the metal is immersed in an electrolytic solution, often acid-based, and an electric current is applied. Oxidation occurs on the surface of the metal, forming a layer of oxide.
• Post-oxidation treatment: after anodizing, the metal is often treated to seal the pores of the oxide and further improve the protection and appearance. This can be done by immersion in hot water or other sealant solutions.

Applications of anodic oxidation

Automotive sector

Automotive components, such as alloy wheels, profiles and structural parts, are often given anodic oxidation treatment to improve corrosion resistance and aesthetics. The benefits include increased durability and maintenance of appearance, reduced maintenance and improved visual appeal.

Aerospace sector

Electronics sector

Anodic oxidation is also applied to electronic and connectivity components, such as housings and contacts, to ensure adequate protection against wear and environment. The benefits include improved corrosion resistance and electrical insulation, longer component life.

Furniture and design

In furniture and design, anodic oxidation is used to achieve aesthetic and durable finishes on decorative and structural elements. The benefits include a wide range of finishes and colours combined with extended durability without fading or wear.