Extrusion process pushes magnesium into structural components

Magnesium is 75 per cent lighter than steel, 33 per cent lighter than aluminium and is the fourth most common element on Earth behind iron, silicon and oxygen. Despite its light weight and natural abundance, the metal requires rare elements such as dysprosium, praseodymium and ytterbium to give it the requisite strength demanded in structural components.

Initial research, described recently in Materials Science and Engineering A, and Magnesium Technology, found the Pacific Northwest National Laboratory (PNNL)-developed process greatly improves the energy absorption of magnesium by creating novel microstructures which are not possible with traditional extrusion methods. It is also claimed to improve the material’s ductility.

"Today, many vehicle manufacturers do not use magnesium in structural locations because of the two Ps; price and properties," said principal investigator and mechanical engineer Scott Whalen. "Right now, manufacturers opt for low-cost aluminium in components such as bumper beams and crush tips. Using our process, we have enhanced the mechanical properties of magnesium to the point where it can now be considered instead of aluminium for these applications - without the added cost of rare-earth elements."