Zinc is a versatile metal that offers many advantages to product development and manufacturing, yet many products designers and engineers are fully aware of these benefits. Zinc die casting is an optimal choice for the right casting. Dave Magner, Vice President of Sales, and Marketing at Deco Products talks with us to understand when zinc is a good choice and how it impacts both product design as well as manufacturing and profitability.

What is Zinc Die Casting and how is it different from other types of metal casting?

Zinc die casting is very similar to other forms of metal die casting. The diecasting process, regardless of the metal, you usually have a mold that can split in half, and you shoot the metal into the two halves as they're pressed together. You let the metal solidify, and then you split the two halves apart and have to extract the part. And then from there you're going to have some excess material as the material flows through and solidifies. And we call that a runner or the gate or the overflow. And so that has to be trimmed off. And then that might be the functional part. It may be that simple, but from there, often there may be some secondary operations that one would need to do to make that part per print and per the specific specifications for the application.

The Differences Are:

Lower Melting Point

Zinc has a lower melting point than other metals like aluminum or steel. The difference in using zinc
it generally runs quicker because it does solidify quicker with the lower melting temperature. Zinc is much more tolerant for varying wall thicknesses because the zinc cools at a more constant rate, even in a thinner and a thicker wall. And so, you'll get a better surface finish with a zinc part.

Zinc is Heavy

Zinc is a heavy material and very dense material. If the weight is a parameter that that design engineer is really factoring in for fuel efficiencies and other reasons, zinc is not going to be the first choice of material. But there are times where weight and the perception of heavier material give the end user a very premium feel. So, there'll be automotive applications where the door handle will be made out of zinc, even though it weighs a little bit more. The perceived value is so much better. You'll see that in a luxury car. Same thing with windows, right? Yeah. The hardware aspect is so important where the value and the perceived value is so much higher on a zinc part, both because it feels better, and it looks better.

Zinc is More Fluid When Casting

Zinc also can fill a mold easier than other metals, so finer design features can be put into the mold both for a better look and reduce the cost of having to machine the details into the part.

Zinc is Less Abrasive

Zinc is less abrasive than aluminum or steel, this means the molds used to die cast the part have less wear and tear and last longer. In fact, a zinc die cast mold will last ten times longer that a steel mold.

Designing & Manufacturing with Zinc

When you're working with a design engineer, there are two sides of the coin that need to worry about. One is, should the part be made out of zinc or not? If zinc is the material in the diecasting process is a strong candidate, then it's a matter of looking at that design and balancing the requirements of the design, the geometry, the testing requirements, things of that nature with what's manufacturable.

This is a real collaborative effort, because sometimes designers will add a feature where we'll ask, well, can that feature be slanted? Or what we call, can we add draft to that? Because we want that part to be less blocky and have filets and be tapered in a lot of ways, what we call draft, so that the part falls out of the tool much more easily. That improves the surface finish of the part and ultimately the quality of the part from day one, but then also the tool life and the quality of that part a year later, even ten years later.

Secondary Operations with Zinc

We talk a lot about the casting process, but then there are secondary processes that are important to add functionality or make the part ready for assembly. That could include machining, adding taft holes, could be powder coating or other decorative or non-decorative corrosion protection finishes. And then just the assembly process. A lot of Deco's background is in the hardware, whether it's window, door. And you can think about the different mechanisms that one could use. Zinc on windows and doors. And when we talk about the door, the egress or ingress access system needs to be something that functions really well, is strong, but also has this great perceived value.

Dave Magner is the Director of Sales and Marketing at Deco Products.

www.decoprod.com

What Advantages Can Zinc offer over Other Metals or Plastics?

Zinc is an element that has certain characteristics that when refined and processed is an excellent choice for making castings and coatings. Zinc offers many benefits that lend themselves to the die casting industry. Zinc is lighter in weight, offers significant reduction in wear and tear to the molds used which extends the life of the casting mold, the material itself is more cost-effective in specific applications as compared to aluminum, plastic, or most cast irons.

Zinc material is categorized by a series of alloys that when used in die casting offer an exceedingly high strength which means thinner Parts can be thinner walls on the castings can be produced. zinc also melts at a lower temperature which makes the liquid form of the metal more vicious and enables it to better fill smaller details with the mold cavity meaning it can go into tighter corners and more details compared to other materials. because zinc melts at a lower temperature it also solidifies at a much faster rate than other metals this helps reduce production time and enables more products to be made in a shorter amount of time than other metals.

Because zinc produces a better net shaped product details like threading can be directly cast into the product and thus reduce secondary operations like machining or even assembly, this helps reduce overall manufacturing costs and production time.

Zinc also offers a longer to life for the molds used in the casting in fact a typical zinc mold can last 10 times longer than an aluminum mold because zinc has fewer abrasive qualities and a lower melting temperature which does less damage to the tooling enabling it to last for a longer life cycle and reduces mold replacement costs.

When to Consider Using Zinc?

The materials used for developing a new product are selected at the design phase. This is where zinc should be considered as the material for use in manufacturing the product.

Zinc is not perfect for all applications, but it is well worth the investigation to see if it can reduce cost or improve quality or reduce the amount of secondary operations in producing a new product. The podcast is an interview with Dave Magner from DECO products (a leading zinc die caster in Iowa) that explains the advantages of zinc die casting in the manufacturing process and the types of products that zinc is best suited for. 

Many Thanks to Dave Magner | Deco Products - https://decoprod.com/