A surge in interest over the past decade has revealed how magnesium alloys and coating techniques can make the most of its attractive properties:
Magnesium is extremely light: it is 75% lighter than steel, 50% lighter than titanium, and 33% lighter than aluminum.
It has the highest known damping capacity of any structural metal, capable of withstanding 10x more than aluminum, titanium, or steel.
It is very easy to machine, and can be injection molded.
Magnesium is entirely biocompatible, posing no toxicity hazards.
On the other hand, it has some well-known shortcomings that limit its wider applicability.
The metal is chemically highly active, so chemical and corrosion resistance tends to be low
Low surface hardness, like aluminum, makes it difficult to use in tribological applications without a coating
Perennial concerns about flammability sometimes rule out the use of magnesium, sometimes without justification. Nonetheless, this aspect should still be considered as part of a holistic material selection process.
Magnesium’s high reactivity had made it susceptible to corrosion. However, recently discovered alloys and higher-purity variants of traditional alloys have a much greater resistant to corrosion, and new coating techniques such as plasma electrolytic oxidation (PEO) make a thoroughly resistant neutral oxide from the metal’s substrate.
Magnesium’s poor creep resistance had made it unsuitable for high temperatures, but recently discovered alloys such as ZE41 & ZWO8203 are heat resistant at extreme temperatures (c. 400 F). PEO coatings also make magnesium extremely heat resistant.
Magnesium’s low tensile strength had made it unsuitable for structural uses, but new alloys and coatings mean this is no longer the case.
As a result of these developments, magnesium is increasingly being used in a range of settings:
Car seats, power tools, luggage, and cameras have all been designed to make the most of lightweight, strong magnesium.
High-performance mountain bike frames and wheels are increasingly made of lightweight, corrosion-resistant magnesium.
The aviation and automotive industries are increasingly looking at ways magnesium can increasing fuel efficiency and reducing greenhouse gases.
Complex, light, and strong components such as those found in engines can easily be molded out of magnesium.
Exciting developments in magnesium alloys, manufacturing methods and coating technologies are making magnesium an increasingly viable candidate for a strong, lightweight, and cost-effective solution.