In 2013, the use of magnesium worldwide exceeded 620,000 tons and has not stopped rising. Due to its beneficial and unique properties, the metal and its many alloys have quickly become a favorite among a broad spectrum of markets. Beyond simple manufacturing benefits, many also see it as a way to aid in increased fuel efficiency and reducing emissions made up of greenhouse gases.
The Wonder Metal
Overall, magnesium is proving to be better than both aluminum and steel in terms of weight. Though lighter than both, it still retains the qualities needed by such a metal to maintain its usefulness. This includes a phenomenal strength to weight ratio, a high damping capacity and a very good fatigue strength. Beyond this, it is nonmagnetic but still retains great conductivity for heat and electricity while being able to shield other metals from electromagnetic shocks. It is even dent resistant.
When it comes to shaping magnesium, no other metal comes close in terms of ease and capability. As far as structural metals are concerned, magnesium is the easiest to mold by machine through virtually any process around. While these properties certainly make it the absolute best option around for virtually everything, it does have a weakness. Magnesium is actually extremely weak when faced with external corrosion, namely in areas where salt-sprays are used. Because of this, plating on magnesium has become the sole way to make this metal usable in all situations without breaking down too quickly.
When it comes to plating on magnesium, there are as many options as there are for the use of the metal. The plating option chosen is what determines the additional properties the metal will receive beyond what it already exhibits.
Electrochemical plating is the best choice when manufacturers want magnesium that is both wear and corrosion resistant as well as having a more decorative look. It is also an extremely cost effective method due to its simple nature. For those familiar with this type of plating, it will come as no surprise to learn that there are two types: electroplating and electroless. The key difference between the two is that one uses an electric charge while the other doesn’t.
Conversion coatings happen when a metal is treated in such a way that it produces a superficial outer layer of compounds that then chemically bind to the surface. For better magnesium, this typically involves an option that protects the metal from corrosion through insulation. Like electrochemical plating, there are quite a few variations depending on what manufacturers desire the final outcome to be.
Anodizing is for a coating that is much less about a fine coating and more about producing a thick film. This film can then be colored. Because it naturally comes with pores that would otherwise allow corrosion to occur, the entire thing must be sealed entirely. The process for this is relatively simple, requiring only steaming or boiling.