General Motors is testing a thermal-forming process and proprietary corrosion resistance treatment for lightweight magnesium sheet metal that will enable the increased use of this alternative to steel and aluminum. GM is aiming to increase its use of low-mass components on vehicles around the world and is intending to pursue licensing opportunities related to this breakthrough technology.
The carmaker’s goal is to enable its parts suppliers to use the process to provide significant amounts of magnesium sheet that will cut more weight from vehicle mass. The lightweight magnesium -- which weighs 33% less than aluminum, 60% less than titanium, and 75% less than steel – is expected to help customers save more money on fuel, just like the benefits brought by efficient conventional engines and electric powertrains.
Carmakers have been struggling to create strong yet reliable non-corroding magnesium sheet metal panels using traditional panel forming methods. But GM’s patented process heats up the magnesium to 450 degrees Celsius (842 degrees Fahrenheit), allowing the material to be molded into precise, rigid shapes.
With this thermal-forming process, GM was able to develop a production-ready magnesium rear deck lid inner panel that withstood 77,000 robotic slams and 250-kilogram impact drops without any issues. While die-cast magnesium has been used in several components like steering wheels and engine cradles, GM is the first carmaker to use thermal-formed magnesium sheet metal in structural applications.
GM said that it expects magnesium sheet applications to grow with additional materials and process improvements aimed at cutting cost. Jon Lauckner, GM chief technology officer and vice president of Global Research & Development, said that GM’s innovative use of magnesium is just one example of how the carmaker is leveraging breakthrough technologies that will benefit its customers around the world. He added that using high-strength lightweight materials like magnesium and aluminum is one of the most effective ways to improve vehicle fuel economy and driving performance.