When designing components and selecting the right material, most engineers focus heavily on the weight of the material, which is why zinc is often overlooked when it comes to lightweight die casting applications. Many applications require parts to be lighter—especially in automotive and handheld device applications—so engineers choose aluminum or magnesium when really, zinc could be a more economical choice. At a quick glance one would assume that there is no place for zinc in lightweight applications, but if we look at the entire die casting process as a whole, can the pros outweigh the cons when it comes to lightweight zinc components?
Zinc is the most fluid of all alloys; it is no wonder die cast manufacturers like working with it. What most engineers don’t realize is that because of zinc’s greater fluidity, die castings can be made thinner, more intricate, and more complex, eliminating the need for secondary operations that are almost always necessary for aluminum and magnesium alloys. With less material being used in thin-wall applications, parts automatically become lighter, creating savings in material cost and energy—when melting and recycling.
Extended Die Life
One of the biggest upfront costs in die casting is the investment in quality tooling. The tools used in the die casting process are usually heat-treated steel. The cost of tooling varies depending on the size and complexity of the component as well as the tooling type—conventional or multi-slide. Due to the low melting temperature of zinc die casting alloy, dies for zinc parts can last up to 10 times longer than dies used for aluminum and about five times longer than dies used for magnesium. When designing high-volume, complex components, zinc becomes extremely cost effective when taking into account the tooling investment.
During the die casting process, molten metal is injected into the die to create the part. When the metal is solidified, the component is then ejected from the tool. Cooling time in the tool varies depending on the alloy and the size of the part and is often dictated by the size of the runner system. Zinc utilizes the hot chamber die casting process, which yields four to five shots per minute. Aluminum is a cold chamber die casting alloy only yielding two to three shots per minute. Since cycle time can determine up to 60 percent of the final part cost, using a zinc die casting alloy could offer added savings.
Did you know that our proprietary multi-slide zinc die casting process can achieve upwards of 45 shots per minute?
Standard zinc alloys are stronger than aluminum and magnesium alloys at room temperature. Strength is inherent in the alloy itself and does not require secondary processing like most aluminum alloys—this saves on the overall cost per part.
EZAC is an alloy offered by Dynacast that is stronger and harder than any other die casting alloy. It is approximately 2.5 times stronger (yield strength) and 1.5 times harder (Brinell) than the most common aluminum die casting alloy, A380. With its zinc characteristics, EZAC is a great option for those seeking a high-strength, creep resistant alloy.
Try our interactive metal selector tool to compare physical and mechanical properties of other die cast alloys.
Dynacast has over 80 years of experience in the die casting industry. Year after year our team of engineers improve and optimize our zinc die casting machines and our processes to provide the best, quality service to our customers all over the world. Contact our team today to learn more about our die casting capabilities and let us help you determine if zinc is the right fit for your next project.