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 for how long their metal component can withstand certain environments while maintaining functional integrity. While some customers are more concerned with the aesthetics of a part, others rely solely on the component's functionality for long-term wear and tear. The good news is that we offer alloy options for any component function.

Aluminium die casting & corrosion resistance

If you are looking for a corrosion-resistant alloy 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 presented an apparent risk of corrosion, aluminium components will typically last longer compared with other die-cast alloys. Aluminium can "heal" itself over time, even after corrosion has affected the exterior of the component. When functionality is imperative for your component, you can rely on aluminium to withstand some of the most demanding working environments.

Our customers often use aluminium to manufacture electronic component housings, lighting fixtures, marine hardware and antennas—among many other applications. While raw aluminium material may not be as visually appealing, its corrosion protection is highly durable, and it offers several surface finish options, 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 simply behave somewhat differently from aluminium-based alloys. While aluminium can "self-heal", zinc will eventually break down and degrade over time. However, depending on the working environment, zinc can last just as long as aluminium and offers more options for 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 use 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 offer all the same surface finish options as aluminium, plus additional options, including:

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

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

Choosing the right alloy

When choosing the best alloy for your project, it is best to speak with one of our engineers to determine the requirements of the specific application. If your part requires a more 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.