Coil Development for Electromagnetic Corner Fill of AA 5754 Sheet
Loading...
Date
2012-07-18
Authors
Journal Title
Journal ISSN
Volume Title
Publisher
Abstract
Electromagnetic (EM) forming is a high-speed forming process that uses the forces
induced on a conductive workpiece by a transient high frequency magnetic field to form
the workpiece into a desired shape. It has been reported by several researchers that EM
forming (EMF) increases the formability of hard-to-form aluminum alloy sheet under
certain circumstances. EMF can be combined with conventional forming (e.g. stamping)
operations to create a hybrid forming operation that exploits the strengths of each
process. One such operation is the “corner fill” operation, which consists in pre-forming
sheet using conventional forming and then using EMF to reduce the radii of different
features on the part to values that could not be obtained with conventional forming. This
paper describes the development of a coil used for a hybrid operation that consisted on
pre-forming AA 5754 1 mm into a v-shape with a 20 mm outer radius and then reducing or
“sharpening” the radius to 5 mm using EMF. The coil is one of the most important
components of an EMF operation, since it is the means of delivering the energy to the
workpiece. Coils are subjected to very high stresses and are typically the element of an
EMF operation that will fail first. One successful and four unsuccessful coils designs are
presented. The successful coil was a single loop design, with the section closest to the
part narrowed to increase the current density. The simplicity of the shape was chosen for
its current flow characteristics and for its structural strength.
Description
Table of contents
Keywords
coil requirements, high speed forming, hybrid forming research, successful coil designs, unsuccessful coil designs