Finishing: Anodizing

anodized metalWhat is Anodizing?

Anodizing is an electrochemical process used to increase the thickness of the natural oxide layer of a metallic surface. This process is used to form a protective coating on the metal while preserving its natural texture and beauty. Anodizing is commonly used on aluminum; however, there are processes available for other metals such as titanium, zinc, and magnesium.

 

Type 3 Anodized partsThe Anodizing Process

Aluminum (the anode) is immersed in an acid electrolyte bath where an electrical current is passed through it. The current releases hydrogen at the cathode (which is mounted inside the tank) and oxygen at the surface of the aluminum, creating a build-up of aluminum oxide. Voltage typically falls in the range of 15 to 21 V; however, higher voltages may be necessary for thicker coatings formed in sulfuric and organic acid. The process leaves a porous coating which is then sealed with colored dyes and/or chemical compounds to prevent corrosion.

 

Uses/Benefits of Anodizing

Anodizing provides attractive, durable finishes that are corrosion and abrasion resistant. The versatility offered allows for many different applications such as architectural products, appliances, furniture, medical equipment, and many more.