Zinc's affinity for die casting and its strength provides excellent design flexibility, exhibiting an excellent combination of cost, strength, ductility, impact strength and finish acceptance. Zinc used in die casting is usually alloyed with small amounts of aluminum, magnesium, and copper. These small amounts of alloying materials transform the zinc, which in its pure form is a brittle, low-strength metal, into an excellent engineering material. The zinc alloys used in die casting have high strength and hardness, good ductility and excellent casting properties. For an alloy selection guide see here.
Mechanical properties (strength and ductility) are comparable, or even superior, to many other cast materials such as aluminum, magnesium, brass and cast iron. Zinc alloys have good bearing and wear resistance; performing like traditional bronze bearing alloys in both dry and lubricated conditions. Zinc alloys perform exceptionally well under conditions of moderate, continuous loading (like threaded connections) or short term, high stresses. These alloys are typically not used in applications where high continuous stresses or elevated temperatures are encountered.
Zinc alloys are corrosion resistant under normal atmospheric conditions, in neutral to alkaline pH aqueous solutions and in contact with petroleum products. Like many other metals, the use of chromate or phosphate dip coatings enhances corrosion resistance.
- UTS up to 330 MPa (hot chamber die casting)
- Elongation of 3-6% (depending on alloy and casting parameters
- Excellent impact resistance properties
- Excellent ductility allowing easy post-finishing operations such as bending, riveting, ...
- Excellent friction properties (auto-lubricant properties, advantageous for gears)
- Excellent thermal conductivity making this material an excellent choice for applications requiring fast heat evacuation
- Excellent electrical conductivity properties (similar to brass) for electrical applications
- Excellent EMI (electro-magnetic interference) properties