Zinc alloys are suitable for part manufacturing due to their ductility, impact strength, and low melting point. In addition, the casting process takes place at a lower temperature due to the low melting point of the material. Hence the name “hot chamber die casting process”.
In addition, being a hot chamber process also increases the life of the mold, the time required to change the mold, and reduces costs compared to other materials that are compatible with die casting.
Zinc Die Casting Process
Generally speaking, zinc alloy die casting is a hot chamber die casting process. While the process will change depending on the part size and machine type, there is also a general mechanism, which is as follows:
Step #1: Prepare the Mold
The die casting mold is cleaned to remove impurities. Then, the mold is lubricated to allow for better demolding of the casting after cooling. The first step is concluded by clamping the mold with high pressure.
Step #2: Injection
The zinc alloy is melted and poured into the shot chamber of the injection machine. Note that the shot chamber will be hot because zinc castings are hot chamber die castings. The molten zinc material is then injected into the die casting mold under high pressure.
Step #3: Cooling and Ejection
The zinc is allowed to cool in the die casting mold to form the mold shape. The mold is released and the solid zinc casting is ejected from the mold.
Note: Make sure the casting is cooled and solidified before demolding.
Step #4: Trimming
Along with other finishing processes, trimming involves removing excess metal that occurs due to die casting defects. Trimming can be done using trimming dies, saws, or other procedures.
Note: Trimmed zinc castings can be recycled and reused.
Application Areas
Automotive Industry
Zinc castings are suitable for manufacturing a wide range of automotive industry internal components. The material is preferred over aluminum due to its strength. Examples of automotive zinc alloy castings include bearings, steering, and brake components.
Note: Zamak 2 zinc alloy is the most popular zinc alloy due to its hardness and strength.
Electronic Industry
Zinc alloy castings are also suitable for manufacturing components used in the manufacture of electronic parts such as energy regulators, toggle switches, wall clocks, and ceramic packaged resistors. Here, dimensional stability comes into play. Hence, Zamak 3 alloy is best suited for making electronic parts.
Home Appliances
Zinc castings are suitable for making home appliances such as belts, furniture inserts, keychains, shoe buckles, door locks, handles, etc. Here, its strength and dimensional stability increase its use in home appliances.
Mechanical Sector
Zinc alloy castings are also suitable for making engine parts used in the mechanical sector. Here, properties such as creep resistance and hardness come into play. Hence, the material is more suitable than materials such as aluminum.