Each zinc alloy offers a specific mix of material properties. In this section, we will discuss some popular zinc alloys. Some of the main alloying elements for zinc are copper, tin, magnesium, and aluminum.
Zamak 3
The Zamak family of zinc alloys has the most common zinc alloy grades, with Zamak 3 being the standard among them. Zamak 3 contains 96% highly pure zinc with 4% aluminum. Furthermore, certain variants within Zamak 3 may also contain trace amounts of copper, magnesium, and iron.
It offers a combination of ductility, strength, finishing, and dimensional stability. These qualities, augmented by its melting point of 384oC, render it highly castable. Therefore, casting is arguably its most popular industrial usage.
Additionally, Zamak 3 also has the characteristic corrosion resistance and electrical conductivity of zinc alloys.
Zamak 5
Zamak 5 is another zinc alloy grade from the Zamak group. Its composition contains ~1% copper in addition to the 4% aluminum, which is common among all Zamak grades.
This addition of copper adds strength and hardness to the zinc alloy. However, these properties come at the expense of decreased ductility and dimensional accuracy. Overall, however, Zamak 5 makes for a great zinc alloy with good castability and machinability.
ZA 8
ZA 8 is a zinc-aluminum alloy with 8.4% aluminum content. Its main qualities include high strength and hardness, as well as creep strength, which is a unique property among zinc alloy grades. Also, it supports various surface finishing processes and is thus a common choice for making items for decorative purposes.
One of its main advantages is its compatibility with die-casting methods, including hot chamber die-casting. Its fluidity allows for casting complex geometries with thin features.
EZAC
EZAC is an innovative zinc alloy grade with aluminum and copper content. It has remarkable strength, hardness, and creep performance, oftentimes quoted as the best among common zinc alloy grades.
It is especially suitable for die-casting applications due to its melting point and fluidity. Its low melting point means that it is compatible with hot chamber die casting, increasing its potential applications in several industries.
ZA 27
ZA 27 is another high-aluminum content zinc alloy, with around 28% aluminum and 2.5% copper. It is lightweight, strong, hard, and has good creep properties. In addition, it has a relatively high melting point among zinc alloys, making it suitable for cold chamber die casting.
Tombak
Tombak is primarily a brass alloy with around 5-20% zinc content. It is known for its low cost, malleability, and shiny appearance. Depending on the composition of other alloying elements (tin, copper, lead, etc.), it can take different colorations.
It is a popular choice for making products of ornamental value like medals, decorative pieces, and buttons due to its gold appearance.
