zinc aluminum is a die casting alloy that offers excellent physical properties for the manufacturing process and good corrosion resistance properties for the finished part. It is also suitable for a wide range of surface finish processes including plating, painting and chroming.
There are two basic families of zinc die casting alloys. The conventional, or ZAMAK alloys, are commonly named based on their sequential development; these include Alloy 3, Alloy 5, and Alloy 7. The high-fluidity or HF zinc alloys have been given a numerical designation that reflects their approximate percent aluminum content; these include ZA-8, ZA-12 and ZA-27. The ZA alloys have higher strength and useful bearing properties than the ZAMAK alloys.
Why do the different alloys differ?
Pure metals like aluminum and zinc are very soft, mainly due to their large atomic mass and size. In fact, it’s nearly impossible to make a single element made of just these 2 elements, as they are amphoteric and cannot be dissolved in an aqueous solution separate from each other without forming dross (a mixture of zinc and aluminum).
The only way to obtain the distinct characteristics that each alloy provides is by using a complex formulation that controls the percentages of each element and the overall ratio of the alloy. The precise percentages must be measured and verified throughout the entire manufacturing process to ensure that the alloy has been formulated to produce its intended characteristics. This is accomplished through a technique called Optical Emission Spectrometry, or OES.