When choosing the right die casting alloy for your next die cast part design, there are many things to consider, including whether or not the metal will rust. A zinc casting is a popular choice due to its strength and resistance to corrosion. Let’s take a look at the properties of a zinc die casting and discuss what happens when this special material is exposed to the environment.
Zinc alloys undergo oxidation when exposed to air, creating a protective layer on the surface.
Does zinc rust? The short answer is that a zinc die casting will not rust when exposed to air, however, it may corrode with a protective barrier of
It is important to understand that even though zinc alloys can corrode they will not rust. Rust is a type of corrosion characteristic to iron-based metals, such as steal, but not zinc alloys. So even though a zinc alloy will corrode it will not rust. In fact, the corrosion of zinc can make the material more desirable choice.
The durability of zinc-based alloys is due to their ability to undergo oxidation when exposed to air, forming a protective layer on the surface. This layer, known as a patina, offers protection from corrosion. When the patina is broken through abrasion, it will naturally reform. This “self-healing” is an important feature of zinc alloys when exposed to the environment.
Zinc alloys can corrode excessively from harsh chemicals or saltwater environments therefore, it is important to protect a zinc casting from these elements. This type of corrosion would create a zinc oxide which would tarnish the part or create a “white rust”. An additional coating can be applied to the zinc alloy, such as a paint, powder coat, or plating (decorative or zinc plated) to increase the long-term appearance of the zinc surface finish.
Zinc die casting: A good choice for part design.
In conclusion, zinc corrodes when exposed to moisture and other environmental elements. However, the corrosion that develops does not rust in a brown and orange color or significantly weaken the part. In this way a zinc die casting is affordable and durable and can be used in a variety of industries. With these design considerations, a zinc die casting process can provide a long-lasting and reliable product.
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Dave Magner
Dave Magner is the Director of Sales and Marketing and has been with Deco Products since 2015. He has a +20 years of engineering experience in mechanical and electrical testing and design and zinc die casting, plastic injection molding, stamping, assembly, and automation processes.
