Corrosion Resistance: Die Casting Alloys

Corrosion resistance refers to how well a metal withstands damage caused by oxidisation or similar chemical reactions—usually over time. For many of our customers, this translates to how well and how long their metal component can withstand certain environments while still maintaining functional integrity. Whereas some of our customers are more concerned with the aesthetics of a part, others rely solely on the functionality of the component for long-term wear and tear. The good news is, we have alloy options for whatever your component function.

Aluminium Die Casting & Corrosion Resistance

If you are looking for a corrosion-resistant alloy that is capable of withstanding high temperatures (200 degrees Fahrenheit or more), aluminium may be the best fit for your project. While exposing aluminium to extremely harsh conditions has always held an apparent risk of corrosion, aluminium components will typically last longer—compared to other die cast alloys. Aluminium has the ability to "heal" itself over time even after the exterior of the component has corrosion. When functionality is imperative to your component, you can count on aluminium to withstand some of the toughest working environments.

Our customers often utilise aluminium to make electronic component housings, lighting fixtures, marine hardware, and antennas—among many other applications. While the raw aluminium material may not be as appealing to the eye, the durability of corrosion protection is top-notch and it has several different options when it comes to surface finishes, including:

• Anodising
• Painting
• Powder coating
• Teflon Coating
• Plating
• E-Coating

Zinc Die Casting & Corrosion Resistance

All zinc-based alloys have excellent corrosion resistant properties; they just act a little differently than aluminium based alloys. While aluminium has the ability to "self-heal," zinc will eventually break down and degrade over time. However, depending on the working environment, zinc has the ability to last just as long as aluminium and it has more options when it comes to surface finishes. If a cosmetic finish is more important than long-term durability, zinc may be the right fit for your project.

Our customers often utilise zinc for decorative and functional applications that do not require high temperatures (below 250 degrees Fahrenheit) such as consumer electronics, key fobs, and kitchen appliances—to name a few. Zinc alloys have all of the same surface finishing options as aluminium plus more, including:

• Different plating options
• Electrocoating (e-coat)
• Chromate

At Dynacast, we offer K-alloy, a high corrosion resistant aluminium-based alloy with superior properties that eliminate secondary anodising and coating.

Choosing the Right Alloy

When it comes to choosing the best alloy for your project, it is best to speak with one of our engineers to determine the needs of the particular application. If your part requires more of a cosmetic finish, we will most likely recommend zinc. The most important thing to know is that we will work with you to define the right alloy for the right application.