Most of the applications of magnesium in lightweighting commercial cars and trucks are die castings rather than sheet metal, and automotive applications of magnesium sheet have typically been experimental or low-volume serial production. The overarching objective of this collaborative research project organized by the United States Automotive Materials Partnership (USAMP) was to develop new low-cost magnesium alloys, and demonstrate warm-stamping of magnesium sheet inner and outer door panels for a 2013 MY Ford Fusion at a fully accounted integrated component cost increase over conventional steel stamped components of no more than $2.50/lb. saved ($5.50/kg saved). The project demonstrated the computational design of new magnesium (Mg) alloys from atomistic levels, cast new experimental alloy ingots and explored thermomechanical rolling processes to produce thin Mg sheet of desired textures. A new commercial Mg alloy sheet material was sourced and pretreated with protective coil coatings, and its properties fully characterized. The Mg sheet was successfully warm-formed using novel lubricants into intermediate size benchmark parts and full-size automotive door inner and outer panels. The project also explored conventional welding processes for joining of Mg sheet, developed novel corrosion treatments for multi-metal assembly coatings, performed computer simulations of door panel forming using two new material cards based on crystal plasticity theory, and concluded with a door static and dynamic performance analysis. An overall cost driver and sensitivity assessment task compared the final cost penalty depending on the cost of the primary magnesium sheet.
