All About The Zamak Alloys - What Are They And What Types Are There?

There are many different alloys used in die casting. Zamak is one of the best known one and it is important to understand all about the Zamak alloys if you want to be involved in this field of work. Basically, Zamak alloys are a family of alloys that all have zinc as their basis. When you learn all about the Zamak alloys, you will quickly find out that they are paired with magnesium, aluminum and copper to create the end product. True Zamak alloys, however, are part of the aluminum family and they have a constant composition of 4% aluminum. Zamak is actually a German acronym, meaning Zink, Aluminum, Magnesium and Kupfer (German for copper). The first company to develop Zamak was the New Jersey Zinc Company, who created it in 1929. Zamak has far higher industry standards than white metal or pot metal, common denominators for other zinc alloys.

All About the Zamak Alloys - the Different Types

There are a number of Zamak alloys. The most commonly employed type is Zamak 3. However, Zamak 2, 5 and 7 are also still found in different commercial applications. When you learn all about the Zamak alloys, you will find that they are most often used in die casts. Zamak 3 and 5 are also used in spin casting.

The Problem with Zinc

Before Zamak, zinc die casting had a huge problem, which was zinc pest. This led to impurities in the alloys made with zinc. What Zamak did was to use 99.99% pure zinc, created by New Jersey Zinc. They did this by using a refluxer during the process of smelting. Thanks to this process, the alloy become far more pure and zinc pest was eliminated. Zamak is incredibly useful, because it can be wet painted and electroplated and it is also possible to coat it in chromate conversion.

All About the Zamak Alloys - What about Mazak?

Morris Ashby, in the United Kingdom, licensed the New Jersey Zamak in the 1930s. It was not available in the United Kingdom at that time, so Ashby brokered a deal with New Jersey Zamak to create Mazak. Mazak is the same alloy, but it is created with zinc that has been electrolytically refined and its purity is 99.95%. The name distinguishes it from Zamak, combining the fact that it is not exactly the same alloy with the name Morris Ashby. However, by 1933, the refluxer was patented by the National Smelting and they then started to produce 99.99% zinc in their Avonmouth plant. As a consequence, Mazak no longer really exists, being exactly the same as Zamak.

The application and the production of Zamak hasn't changed much over the past 80 years or so. Zamak is depicted using a series of codes that indicate exactly how it is made. A good example is the code ZL0430. Here, Z stands for zinc, L stands for ingot (this can also be P for pressure die casting). The 04 means the percentage of aluminum in the alloy (04 being 4%) and the 3 is the percentage of copper (in this example, it is 3%).