Anodizing Explained
While aluminum is generally very corrosion-resistant, it can corrode or tarnish under certain circumstances. Anodizing aluminum is an effective way to enhance its already high corrosion resistance. It also provides a more attractive and consistent finish that, unlike coatings, won’t chip or flake off over time.
The anodizing process involves treating the aluminum with an electrolyte bath, in which a cathode is placed into an anodizing tank, making the aluminum function as an anode. A current passes through the electrolytic medium, creating an oxygen reaction on the aluminum’s surface and deep into the metal’s pores. What results is a protective anodic layer, and the longer it’s exposed to the electrolyte bath, the thicker it becomes.
This anodic layer resists wear and corrosion even more than regular aluminum. It also creates a polished appearance with a natural metallic color. Because the anodized layer is formed by a chemical reaction, it’s 100% pure, fully recyclable, and it won’t chip or peel.
Types of Anodizing
There are several types of anodizing services available, each with unique properties and industrial uses.
- Sulfuric Acid Anodizing: Sulfuric acid is one of the most popular and cost-effective anodizing services available. It’s particularly useful for applications requiring harder surfaces and high resistance to abrasions, such as mechanical hardware and military equipment. The finish is also clearer than other anodizing processes, making color dying highly effective.
- Hard Anodizing: Even greater hardness is achieved through a denser sulfuric acid compound, resulting in a much thicker and sturdier finish. Hard anodizing is useful to achieve a longer material lifespan and greater electrical insulation. This makes it useful for heavy industrial equipment, such as pistons, gears, and valves.
- Titanium Anodizing: Titanium can also undergo an anodizing process, enhancing its utility in the aerospace and biomedical sectors. Three different types of titanium anodizing are available, but only two are commonly used. Type 2 is mainly used to protect surfaces from wear, while Type 3 is primarily used to provide clearer visual differentiation between parts for biomedical companies. The Type 1 anodizing process creates a higher-temperature layer and is only occasionally used.
- Color Anodizing: Applying colored dyes into the anodizing solution makes it possible to thoroughly ingrain color pigment deep into metal pores. The result is a highly decorative material with both high durability and aesthetic qualities. Because the dye is thoroughly ingrained into the material, it can’t be scratched off like superficial coatings.
Advantages of Anodizing
Anodizing services achieve numerous benefits that make aluminum and titanium even more useful. Anodized surfaces are easy to maintain, requiring only water and a mild detergent to restore the anodized surface to its rich, polished metallic appearance. Unlike surface treatments, anodized layers are chemically ingrained into the metal itself, making it highly UV stable and impervious to flaking or peeling.
This further protects the base metal itself, making the entire material more useful under harsh conditions. Many architectural finishes are also available, creating an attractive and polished look for minimal expense.
Anodizing Services From PSI Industries
PSI Industries experienced finishing, assembly, and CNC machining specialists are adept with a wide range of anodizing services, including numerous in-house anodizing processes and off-site finishing capabilities. We maintain an ISO 9001:2015 certification to ensure our clients receive industry-best quality controls and finished products made according to ultra-tight tolerances.
If your company requires professional anodizing services, request a quote, and our dedicated assembly and finishing technicians will be with you shortly.