Latest Monash research reveals technique to shape pure magnesium at room temperature
In a world first which could have major implications for the transport industry, Monash University Engineering researchers have discovered a way to shape pure magnesium at room temperature
A team of Monash University researchers, led by Professor Nick Birbilis from the Department of Materials Science and Engineering, have found a way to change the microstructure of magnesium from that of a brittle structure to one that is malleable (i.e. superformable).
Magnesium is not currently used in the manufacturing of transport vehicles such as cars, because it is intrinsically a brittle metal not known for malleable properties. Usually magnesium is formed at elevated temperatures between 200-400°C; this new technique will reduce energy costs associated with heating magnesium.
Professor Birbilis’ team chose to work with magnesium because it is the lightest structural metal. With a density two-thirds that of aluminium and a quarter of steel, magnesium could potentially replace heavier alloys presently used in car production, resulting in lighter cars, better fuel economy and fewer emissions.
Up until now, most magnesium components in the automotive industry are made using castings for parts such as casings and steering wheels. However, the present research unlocks components that require formability, such as panels.
According to Dr. Zeng, this is a major advantage. “With this discovery, we can expand beyond the application of cast magnesium to super-formable magnesium that can be rolled, bent or compressed into any shape, even at room temperature”.
“Previously no one has made magnesium so workable - but Monash University has!”
The paper, titled “Super-formable pure magnesium at room temperature” just published in the London based “Nature Communications” journal.
“By refining the microstructure we have changed the deformation mechanism from intra granular (brittle) to inter granular (formable)”, post-doctoral scholar Randy (Zhuoran) Zeng says.
The recipe is relatively simple; pure magnesium is pushed through a die at 80°C, then cold-rolled. This process changes the microstructure of the magnesium so that it is no longer brittle. It can be cold-rolled at room temperature to under a millimetre of thickness without cracking. In fact, it simply doesn't crack. “We can even roll it to the thickness of aluminium foil and bend it 180° after rolling”, Dr. Zeng says.
To read the paper in full, please click here.