Zinc and Zinc Alloys Information
Zinc and zinc alloys are non-ferrous alloys that are used widely in the production of die cast components. Zinc-base alloys are used for two main functions, casting and wrought applications.
Casting alloys are used for sand, permanent mold, plaster mold, shell mold, and investment casting. The mechanical aspects of these alloys make them attractive substitutes for cast iron alloys (better corrosion resistance and machinability) and copper alloys (lower cost) in structural and pressure-tight applications. Also, zinc’s low melting point allows for lower energy requirements when casting.
Wrought alloys are obtained as various shapes and exhibit good resistance to corrosion in many types of service. Wrought zinc has chemical characteristics particularly adapted to certain uses, such as dry batteries and photoengraver`s plate. Its elastic module, like many alloys, is not clearly defined and thus creep data is needed to fit the metal to load requirements. Wrought zinc is easily machined using standard methods and tools, but if it is necessary to machine zinc containing very coarse grains, the metal should be heated to a temperature between 70-100°C in order to avoid cleavage of crystals.
Selecting metal alloys requires an analysis of the desired dimensions and specifications. Dimensions to consider include:
- Outer diameter (OD)
- Inner diameter (ID)
- Overall length
- Overall thickness
Other specifications of importance (based on application) include product shape, tensile strength, yield strength, melting point, conductivity, corrosion resistance, ductility, and malleability. These properties differ based on the forming method and alloy composition.
Pure or unalloyed zinc is used in non-structural applications and to galvanize metals such as iron in order to prevent corrosion. Zinc is also used in batteries and as an alloy with copper to make brass.