Zinc Alloy Castings Tailored to Meet your Needs
What is a Zinc Alloy Casting?
Zinc alloy castings are divided into two families, which are the conventional or “ZAMAK” alloys and zinc alloys with higher amounts of aluminum than the conventional alloys. The conventional or “ZAMAK” alloys have names based on their sequential development, preceded by the word “alloy”. The different types of conventional alloys include Alloy 2, Alloy 3, Alloy 5, and Alloy 7. Additionally, the latest addition to the Zamac family is the new high-fluidity or “HF” alloy.
On the other hand, zinc alloys with higher amounts of aluminum than the conventional alloys use the prefix ZA followed by their approximate aluminum content. Some examples of these alloys are ZA-8, ZA-12, and ZA-27. These ZA alloys offer higher strength and useful bearing properties. Knowing the differences between these two families of zinc casting alloys can help you determine which one would be best suited for your specific needs.
Major Alloy Characteristics
Alloy 3, also known as Zamak 3, ZP3, ZL3, ZP0400, ZnAl4, and ZDC2, is a zinc alloy that is extremely popular in North America. This is thanks to its exceptional physical and mechanical properties, long-term dimensional stability, and superb castability. Additionally, Alloy 3 has excellent finishing characteristics for plating, painting, and chromate treatments. It is recognized as the standard by which other zinc alloys are rated in terms of die casting.
Alloy 5, also known as Zamak 5, ZP5, ZL5, ZP0410, ZnAl4Cu1, and ZDC1, on the other hand, is the most widely used zinc alloy in Europe. It has slightly improved creep performance over Alloy 3 but is marginally harder and less ductile, which can affect formability during secondary bending, riveting, swaging, or crimping operations. When a higher measure of tensile performance is needed, Alloy 5 castings are recommended, and they are easily plated, finished, and machined compared to Alloy 3.
Alloy 7, or Zamak 7, ZL7, is a modification of Alloy 3 with a lower magnesium content and tighter impurities specification. This results in improved casting fluidity, ductility, and surface finish, making the alloy popular for making thin-walled components that require a good surface finish.
Alloy 2, or Zamak 2, ZP2, ZL2, ZP0430, ZnAl4Cu3, and Kirksite, offers the highest strength and hardness of the conventional zinc alloys, thanks to the high copper content (3%) in it. However, this results in slight dimensional growth, reduced impact performance, and lower elongation for die cast products upon long-term aging. Alloy 2 exhibits excellent castability and maintains higher strength and hardness levels after a long period.
A newly developed High Fluidity Alloy (HF) possesses up to 40% better fluidity while sharing excellent mechanical, electric, and thermal conductivity characteristics with the conventional alloys. It is the best choice for casting parts with section thickness less than 0.45mm and for casting parts that are difficult to fill with Alloy 3, 5, or 7 or need high surface finish requirements.
ZA-8, or ZP8, another good gravity casting alloy, is hot chamber die-castable and is readily plated and finished using standard procedures for the conventional zinc alloys, making it the preferred die casting choice where Alloys 3 or 5 performance is in question, due to its high strength and creep properties.
ACuZinc5, although a hot chamber die-casting alloy, has improved tensile strength, hardness, and creep performance compared to conventional zinc alloys, although it is difficult to die-cast with a higher wear rate of the shot end components in the die-casting machine.
EZAC, a newly developed alloy with the most creep resistance of all the zinc die-casting alloys and lower melting temperature, is hot chamber die-castable and does not exhibit the same die casting equipment wear and tear as ACuZinc5.