ZINC ALLOY ZA 8
Zinc-Aluminum Alloy, in short, ZA Alloy, is identified by its significantly higher percentage of aluminum. The higher aluminum content imparts its lightweight property to zinc alloys. ZA 8 technically refers to the fact that the Zinc alloy has approximately 8% aluminum in it.
ZA-8 Alloy Characteristics
ZA-8 is the lightest alloy in the Zinc-Aluminum alloy family that can be hot chamber die cast. Hot chamber casting has many advantages over cold chamber die casting. Therefore, ZA-8 is often preferred over other zinc alloys for die-casting.
The extra aluminum content helps to reduce its weight while improving other material properties. But it also increases the melting point of the alloy. This is why Zinc-Aluminum alloys such as ZA-12 and ZA-27 with higher aluminum content go out of the scope of hot chamber casting.
Advantages
The ZA 8 alloy offers some exclusive benefits over other die casting metal alloys.
- Combines the benefits of the high strength of zinc and the lightweight of aluminum
- Has better mechanical strength than all other hot chamber die cast zinc alloys.
- Exhibits higher creep performance compared to any other zinc alloy
- Has great plating and surface finishing characteristics
- Has enhanced corrosion resistance and doesn’t spark
Applications
ZA 8 Alloy is good for casting decorative products with intricate shapes and thin walls. ZA-8 castings can be given aesthetic surface finishes like chrome plating to enhance the outlook of the end product.
They are also excellent for the production of bearings. Because zinc-aluminum alloy-based bearings have minimal need for wear inserts and bushings.
Mechanical Properties
| Parameters | Value |
| Brinell Hardness | 100-106 HB |
| Ultimate Tensile Strength | 372 MPa |
| Yield Strength (0.2%) | 283-296 MPa |
| Shear Strength | 275 MPa |
| Compressive Strength | 252 MPa |
| Fatigue Strength | 103 MPa |
| Impact Strength | 32-48 J |
| Modulus of Elasticity | 85.5 GPa |
| Elongation | 6-10 % in 50mm |
Physical Properties
| Parameters | Value |
| Melting Range | 375-404°C |
| Density | 6.30 g/cm³ |
| Electrical Conductivity | 27.7 % IACS |
| Thermal Conductivity | 115 W/mK |
| Coefficient of Thermal Expansion | 23.3 µm/m°K |
| Specific Heat | 435 J/Kg. °C |
| Poisson’s Ratio | 0.30 |
Alloy Composition
| Contents | Value |
| Zinc (Zn) | Balance |
| Aluminum (Al) | 8.2-8.8 % |
| Copper (Cu) | 0.9-1.3 % |
| Magnesium (Mg) | 0.02-0.03 % |
| Iron (Fe) | 0.035 % (max) |
| Cadmium (Cd) | 0.005 % (max) |
| Lead (Pb) | 0.005 % (max) |
| Tin (Sn) | 0.002 % (max) |
Limitations of ZA 8 Alloy
While the ZA-8 alloy has the exclusive benefit of being able to cast using the hot-chamber process. You do miss out on the benefits of other ZA alloys such as ZA-12 or ZA-27 have to offer.
Sunrise Metal has both hot and cold chamber manufacturing and in-house surface treatment facilities. You can rely on us for any sort of ZA alloy or Zinc die casting in general.
