GM Touts Magnesium Sheet Processing

General Motors Co. hopes to license technology it has developed to form magnesium sheet metal and treat the material for corrosion resistance.

The challenges of stamping and protecting the metal have limited the auto industry's use of sheet magnesium, which GM notes is 75% lighter than steel and 33% lighter than aluminum.

GM's forming process heats magnesium blanks to 450 C (842 F), which enables them to be stamped into precise shapes. The company used the process to make a production-ready magnesium rear deck lid inner panel that weighs 1 kg (2.2 lbs) less than the same panel made of aluminum.

GM says the prototype part successfully survived 77,000 robotic slams, 250-kg impact drops and 10 weeks of 24-hour salt spray, 100% humidity and extreme temperature tests. The company says it wants its suppliers to be able to use the process to help it reduce vehicle weight.