ZA12
Foundry Zinc alloy.
ZA12 is a zinc base alloy, which conforms to BS EN 1774 and is particularly suitable for the sand or gravity diecasting processes. This alloy is one of a range of three alloys developed by Noranda Research to improve the application range of zinc alloy castings.
Application
This alloy is frequently specified for zinc alloy prototype castings. In gravity cast form its properties replicate the pressure cast properties of ZL 3 or 5, as such it forms a useful media for testing cast applications prior to the manufacture of final tooling.
ZA 12 is used in some of the less common casting processes using plaster, aluminium and graphite tooling. It will produce castings with excellent surface finish from these processes. This combined with reasonable dimensional stability make it ideal for general purpose low volume casting applications where low tooling cost is an important factor.
This alloy is easily machined and possesses excellent bearing properties enabling it to compete favourably with brass, bronze, cast iron and aluminium castings. ZL 12 has good surface corrosion resistance and requires minimum surface preparation for decorative finishes such painting or plating.
The low aluminium content of this alloy allows it to be used for non sparking applications such as under ground mining or hazardous environments. ZL 12 is often specified as an alternative to cast iron and brass where cost reduction is being considered.
| Alloy Designation | ZaAl11Cu1 | Colour code | White + orange. |
|---|---|---|---|
| Short designation | ZL 12 | Alloy Number. | ZL01110 |
| Chemical composition of Ingots. | |||||||||
|---|---|---|---|---|---|---|---|---|---|
| Al | Cu | Mg | Pb | Cd | Sn | Fe | Ni | Si | |
| Minimum | 10.8 | 0.5 | 0.02 | ||||||
| Maximum | 11.5 | 1.2 | 0.03 | 0.005 | 0.005 | 0.002 | 0.05 | -- | 0.035 |
| MECHANICAL PROPERTIES | ||
|---|---|---|
| Supplied in diecast form. | As Cast | Aged |
| Tensile strength | 310 - 345 MPa | -- |
| Yield strength 0.2% offset | 250 - 275 MPa | -- |
| Impact strength | 30 Joules | -- |
| Elongation 50mm | 1.5 - 2.5% | -- |
| Shear strength | 255 MPa | -- |
| Compressive yield strength | 288 - 241 MPa | -- |
| Fatigue Strength | 103 MPa | -- |
| Hardness BHN 500Kg | 85 - 95 max | -- |
| PHYSICAL PROPERTIES | |
|---|---|
| Melting range | 377 - 432° C |
| Density | 6.03 g / cm3 |
| Coefficient of Thermal expansion | 24.1 um/m0 C |
| Thermal Conductivity | 109 W/m0 C |
| Electrical Conductivity | 28.3 % IACS |
| Electrical Resistivity | 6.1 u ohm-cm at 200 C |
