What is Zamak, applications and features

The industrial sectors that choose to manufacture their articles using zinc alloys are constantly expanding, thanks to the increasing awareness of the enormous advantages that this material can bring, in terms of technical performance, to the customer’s final product.

In particular, Zamak is common for the production of automotive components, clothing accessories, handles and components of household appliances, furniture hardware, technical components and small parts of extreme precision.

Zamak is a very appreciated alloy for its properties and increasingly used, as it is very versatile and resistant.

One of the main features of Zamak is its fluidity that makes it ideal for the realization of thin elements and objects with complex and detailed shapes. This feature allows manufacturers to create intricate pieces quickly and accurately.

Zamak also offers good resistance to corrosion, wear, and deformation, making it suitable for applications that require durability and reliability over time.

Zamak is also appreciated for being coated with other materials, such as nickel or chrome, to further improve its corrosion resistance and give it a more attractive appearance.

From an environmental point of view, Zamak die-casting has a lower impact because the speed of the moulding cycles and the relatively low melting temperature allow a considerable energy saving and a reduction of the emissions of the production process and air pollution as a consequence.

The energy savings and reduced production times, combined with the low wear of the moulds and the possibility to obtain parts with almost definitive shape, make die-cast Zamak components economically more advantageous than other materials and production processes.

The Zamak parts at the end of their life cycle can also be recovered and reused as this material can be recast to obtain new ingots of the so-called “second Zamak“.

The low melting temperature, the high fluidity and the high dimensional stability are the characteristics that make Zama suitable for the realization of even very complex components, through the hot chamber die-casting process.

ZL2 alloy is mainly distinguished by its excellent tensile strength and hardness. The ZL3 is particularly appreciated for its impact resistance and dimensional accuracy. The ZL5 alloy, on the other hand, is the most widespread because it combines the tensile strength of ZL2 with the strength of ZL3, as well as providing the best dimensional stability among all die-casting alloys. Finally, the ZL8 focuses on tensile strength, albeit at the expense of resilience, which is significantly lower than that of ZL5.

The percentage elongation at the break of the Zamak goes from 4% to 6%. Compared to aluminium, whose percentage of elongation is about 3%, Zama has significantly higher elongation values at breakage. This means that sudden and unexpected breakages can be avoided by observing the die-cast Zamak jet in an overload situation.

For short-term stresses, the load is determined by the elastic limit of the material. In this respect, Zamak alloys have an advantage over aluminium, magnesium, and plastics.

The maximum yield strength of zinc alloys is much higher than that of other die casting alloys, such as aluminium and magnesium.

The higher yield strength results in a high Zamak capacity:

• in bearing shear forces;
• in undergoing the torsion;
• in resisting bending and compression.

The tensile strength of zinc alloys is higher than that of die-casting alloys, such as AlSi9Cu3 Aluminium or AZ91 Magnesium. Zinc alloys show a high degree of plasticity when subjected to destructive tests of load levels. This feature, combined with the high fluidity of the alloy, makes the designer free to process details with very thin thickness and at the same time very resistant

The impact resistance of the Zamak is very high and the best alloy in this respect is the ZL5.

The hardness values of Zamak alloys are at the top among the production materials for components. They are comparable to those of extruded brass and sintered steel. The hardness of zinc alloys is higher than that of aluminium and magnesium.

In particular, Zamak with higher percentages of copper has a higher hardness. This is certainly an advantage in case the components are used in conditions of high wear.

The thermal conductivity of Zamak is comparable to that of aluminium and much better than that of magnesium or steel. This feature, combined with the possibility of easily obtaining thin walls, offers the designer the concrete possibility of creating dissipation zones integrated in the design of the part.

The electrical conductivity of zinc alloys, defined as the inverse of resistivity, is comparable to that of aluminium and better than that of magnesium. The low electrical resistivity places the Zamak in prominent positions in its use for parts and electronic components.