It's no great secret that in the quest to decrease vehicle
weight, there's been an increase in the use of aluminum for body
panels. However, this poses challenges in stamping due to
aluminum's lower formability compared to steel. In an effort to
overcome this handicap, two researchers at Michigan
Technological University (Houghton, MI) are developing a new die
technology for deep drawing aluminum. As a part of the
Partnership for a New Generation of Vehicles (PNGV), Dr. Klaus
Weinman and Dr. Abhijit Chandra have built prototype dies with
"active" drawbeads, designed to prevent tearing and wrinkling of
the aluminum during stamping. Traditional dies may use fixed
drawbeads to add a consistent frictional resistance to the blank
during deformation, thereby controlling the flow of the blank
into the die. While the Michigan Tech die does have drawbeads,
instead of being fixed, they can be moved via hydraulic
actuators. This allows the user to vary the frictional forces
created by the drawbeads during deformation. B