Zinc vs aluminum alloys
Both zinc and aluminum alloys are popular in the die-casting process for parts in various industries. Die-casting is excellent at producing complex parts, but the resulting parts can only be as good quality as the parent metal.
Whether you choose zinc alloy or aluminium alloy for die casting, the choice depends on important elements like strength, corrosion resistance, weight, and melting point.
Zinc is renowned for corrosion resistance and impact resistance, while aluminum presents a high strength-to-weight ratio.
Below is a brief coverage of the characteristics and properties that differentiate between zinc vs aluminium alloys even more.
What Is Zinc Alloy?
Zinc alloy is a mixture of zinc metal and another metal. Alone, zinc is naturally weak, hence unsuitable for engineering applications. Zinc is popularly added to base metals to form zinc alloys. The brittle metal is therefore mixed with stronger metals for improved properties, including enhanced impact resistance.
Zinc also provides corrosion resistance and malleability to the mixture, making the alloy excellent for fabrication projects, plumbing parts, automotive parts, and so forth.
A zinc alloy plumbing fitting adapter
Properties Of Zinc Alloy
The properties of zinc alloy depend on the specific zinc alloy. There are several zinc alloys, including brass, Zamak, Tombak (Tombac), zinc aluminum, commercial bronze, spin cast zinc alloy, and nickel silver.
Here are some properties of these zinc alloys for comparison.
| Zinc alloy | Properties |
| Brass | Good corrosion resistance, excellent machinability, and castability. Suitable for hardware and fittings. |
| Commercial bronze | Superior corrosion resistance, excellent machinability. Popular for architectural parts and marine hardware. |
| Nickel silver | Good machinability and excellent corrosion resistance. Perfect for springs and electrical contacts. |
| Spin Cast Zinc Alloy | Excellent in castings and can also be machined relatively easily. It is used to make automotive parts and die castings. |
| Tombak (Tombac) | Tombak is super easy to machine and has excellent castability. That explains why many of its parts are in jewelry and decorations. |
| Zamak | Zamak is also easy to machine and cast, but its corrosion resistance is poor. Its uses are in die castings, hardware, and toys |
| Zinc Aluminum | Though not easy to machine, its castability and corrosion resistance are impressive. It is suitable for galvanizing. |
What Is Aluminum Alloy?
An aluminum alloy is a mixture of several metals, with aluminum as the main component. The popular alloying elements include copper, magnesium, tin, silicon, and manganese.
Aluminum alloys have the good properties of aluminum, and blend these with the properties of alloying elements to make superior metals. Depending on the specific alloying elements, aluminum can attain much improved properties, including strength that can match that of some steels.
Aluminum alloys are designated numerals as shown in the table below.
Table 1: aluminum alloys and their main alloying elements
| Numeral | Main Alloying Element |
| 1XXX | None (99% aluminum) |
| 2XXX | Copper |
| 3XXX | Manganese |
| 4XXX | Silicon |
| 5XXX | Magnesium |
| 6XXX | Magnesium and silicon |
| 7XXX | Zinc |
| 8XXX | Other elements |
Properties Of Aluminum Alloy
The main properties of aluminum alloy are corrosion resistance, low weight, a high strength-to-weight ratio, thermal conductivity, and malleability.
Corrosion resistance: Aluminum alloys are naturally corrosion-resistant because of an oxide layer that forms on the surface.
Strength-to-weight ratio: The low density of aluminum (2.7 g/cm³) contributes to the generally low weight of aluminum alloys. Thanks to copper, zinc, and such elements, the alloy is also very strong.
This property makes it popular in aerospace and other industries where a high strength-to-weight ratio is required.
Aerospace aluminum part
Heat Conductivity: Aluminum alloys are capable of transferring heat. At approximately 150 W/(m·K), the thermal conductivity of these alloys is useful in items like electronics, cooking utensils, and car radiators.
Zinc vs Aluminum Alloys: Which One Is Better For Projects?
The key differences between zinc alloy vs aluminum that mean a lot in die casting services are in corrosion resistance, weight, melting point, and the specifics of the die casting process.
Density/Weight
The weight of an alloy is paramount in die casting, and this is the reason aluminum alloys are preferred in this respect. Aluminum die-cast parts are extremely light compared to die-cast zinc alloy parts. Therefore, aluminium die casting applications are where lightweight, strong parts are required.
In terms of zinc vs aluminium for density, zinc die-cast parts outperform aluminum ones. This makes zinc die casting applications suitable in high-impact areas, where aluminum alloys may not work as perfectly.
Melting Point
Zinc alloys have lower melting points of about 350°C to 450 °C compared to those of aluminum alloys (550°C to 660 °C). A lower melting point translates to less production energy, which minimizes costs.
Corrosion Resistance
Zinc alloy die-cast parts have higher corrosion resistance than aluminum alloy parts. Zinc alloy parts are therefore more preferable for applications where corrosion is a serious problem and zinc vs aluminium capabilities are the deal breaker.
A zinc alloy die-cast part
Is Zinc Better Than Aluminum for Die Casting Parts? How Is The Process?
Looking at the die casting process, the difference emanating from the low melting point of zinc is that the process is faster. The hot chamber die-casting approach is doable with zinc.
Hot chamber die casting
Due to a higher melting point, the aluminum die casting requires the alloy to be melted elsewhere before being added to the machine. This can make the process longer.
Which is Stronger? Zinc Die Casting Parts vs Aluminum Die Casting Parts.
Zinc die casting parts are stronger than aluminum die casting parts, and this can be attributed to the higher density of zinc (about 2.5 times heavier than aluminum).
In Conclusion
Whatever option you take in zinc die casting vs aluminum die casting, both options can bring a difference in your die-casting project if done with the right partner. ProleanTech has in-depth experience producing high-quality, complex metal parts from a broad array of metal alloys.
Call today for more information.
FAQ’s:
What Are the Advantages Of Aluminum Die Casting?
The advantages of aluminum die casting include a high strength-to-weight ratio, versatility, quality surface finish, durability, and accuracy.
What Is The Cheapest Material For Die Casting?
Zinc is the cheapest material for die casting due to its low melting point, which makes casting extremely easy.
What is the best aluminum for die casting?
The best aluminum for die casting is A380. This material is not only durable and excellent to cast, but also has good resistance to hot cracking and is cost-effective.


