Why is zinc added to alloys used in die-casting?

Zinc is a primary component in alloys used for die-casting because it enables highly efficient, automated manufacturing processes. When molten zinc-based alloys are injected under pressure into steel dies, they undergo rapid solidification, allowing for high production rates of complex shapes with excellent dimensional stability and surface quality.1

These alloys, which typically incorporate 4 to 5 percent aluminum along with small amounts of magnesium and sometimes copper, are favored because they possess good mechanical properties and a relatively low melting point. The resulting components are durable and versatile, finding widespread use in the automotive industry for functional and decorative trim, as well as in domestic appliances, locks, and various engineering components. Additionally, these castings can be easily plated to achieve highly decorative finishes.12