It’s a given that it will take more than just better powerplants to reach the 54.5 mpg federal fuel economy standard set for coming years. To this end, automakers are exploring every part of an automobile for ways to eke out greater efficiencies.
An interesting new exploration is taking place at General Motors, which is testing an industry-first thermal-forming process and proprietary corrosion resistance treatment for lightweight magnesium sheet metal. GM’s aim is to enable its suppliers to use the process and provide magnesium sheet in lieu of steel and aluminum that trims pounds from vehicle mass.
This is no small thing. Magnesium weighs 33 percent less than aluminum, 60 percent less than titanium, and 75 percent less than steel. Despite its advantages, there have been challenges and automakers have found it difficult to make strong and non-corroding magnesium sheet metal panels through traditional methods. GM’s has now overcome this with a new, patented process that heats the magnesium to 842 degrees F to allow molding it into precise, rigid shapes. GM has used this process to develop a production-ready magnesium rear deck lid inner panel that’s undergone rigorous testing without any issues.
The U.S. Automotive Materials Partnership estimates that 350 pounds of magnesium will replace 500 pounds of steel and 130 pounds of aluminum per vehicle by 2020, achieving a vehicle weight reduction of 15 percent. This weight savings would lead to a fuel savings of 9 to 12 percent.