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.