How To Prevent Aluminum Corrosion

From cars to airplanes, electronic components to kitchen appliances, aluminum is one of the most common metals used to create a variety of products. In addition to being abundantly available, aluminum is a go-to metal for many other reasons. For instance, it's strong, lightweight, and affordable.

But despite all the advantages aluminum poses over other metals, it does come with one notable disadvantage: corrosion. In this post, we'll discuss how aluminum corrodes, why it's a problem, and what you can do to prevent it from happening. Here's a closer look at everything you need to know about preventing aluminum corrosion.

What is Aluminum Corrosion?

So what causes aluminum corrosion? Especially since aluminum is rust-resistant, right?

First, let's be clear: corrosion and rust are not the same things. Rust is when steel, and alloys that contain steel, oxidize and then peel away, typically a result of moisture and other environmental conditions. Rust is red. That red is the steel or the steel in an alloy (like stainless steel), corroding. Corrosion, conversely, is when aluminum oxidizes and gradually decays over time. Aluminum tends to like oxygen, and when it oxidizes, a white surface will begin to form over the metal. While this surface can be scratched off, it will likely form all over again unless the metal is modified or the material is taken out of the environmental conditions that are causing it.

Aluminum can begin to corrode if either chlorides or sulfides are present, which will attack the oxide layer. Aluminum may also corrode via galvanic corrosion. This occurs when dissimilar metals come into contact with each other while in the presence of an electrolyte.

Why is Aluminum Corrosion Bad?

As noted above, corrosion is the gradual decay and degradation of a material over time. As a material corrodes, it will lose its physical and chemical properties. It's common for holes to develop in pieces of the material, which aren't just unsightly but unsafe. Hence, the favorable strength-to-weight ratio and durability of a material like aluminum will essentially become undone as the material corrodes.

How to Safeguard Products from Aluminum Corrosion?

So how can you prevent materials such as aluminum from corrosion? There are a few notable ways to achieve this.

Control the Climate

For starters, you can remove the environmental factors that could cause it. However, this isn't always easy. Controlling the climate in certain areas where aluminum is present can be expensive and complicated. Aluminum is often used in materials that contact environmental elements such as moisture, rain, humidity, and more corrosion-causing agents. Minimize exposure to all of these elements to prevent aluminum corrosion.

Add a Protective Finish

An easier means of preventing aluminum corrosion is to add a protective finish to the material. This additional protective layer can provide the perfect barrier between the aluminum piece and all of the potential environmental hazards that it may come into contact with. Think of how a raincoat repels water and won't let any moisture penetrate its surface to reach your clothing or skin. That's the same effect that a protective coating can have on aluminum materials.

An alternative to performing metal finishing on aluminum is painting the surface. However, this may not offer as reliable a solution as adding a protective finish as a base coating for paint adherence.

Anodizing: What You Need to Know When it Comes to Aluminum 

One of the most popular finishing methods for treating aluminum is anodizing. It's specifically administered to provide corrosion resistance and ensure that the finish of a metal part remains durable and attractive. Various types of anodizing can be allocated based on the application and your end goals.

These include:

• High-precision anodizing: Ideal for applications or high-quality components requiring close tolerances and zero defects. This process is more for high-end aluminum parts. There's also a high-precision hard coat anodizing that applies a thicker coating – usually anywhere in the range of 25 to 50 microns. High-precision hard coating tends to require a greater degree of process control due to the enhanced durability of the hard coat.
• High-efficiency anodizing: This is a more affordable type of anodizing that can process aluminum pieces in higher volumes. Similar to a high-precision hard coat process, there's also a high-efficiency hard coat anodizing process, which is ideal for parts high in volume that require significant durability and corrosion resistance in the aluminum end parts.

It makes sense to add a protective surface finish to your application or parts. Anodizing tends to be the finishing process of choice for aluminum parts. This coating can keep aluminum strong, durable, and corrosion-resistant for the long term.

Prevent Aluminum Corrosion with an Anodizing Specialist

At Light Metals Coloring in Southington CT, we offer protective solutions for your applications and parts. Whether it be to prevent aluminum corrosion or mitigate the effect of galvanic corrosion, you can count on us to provide the best quality and performance for your products.

If you still have any questions about preventing aluminum corrosion, contact a reputable metal finishing specialist for more information about anodizing and what process would work best for your application. Even if it takes a while for corrosion to set in, it's a better strategy to prevent it from happening in the first place.