Single Point Incremental
Forming using a Dummy Plate - Multi Plate Forming
M. Skjoedt1, M. B. Silva2, N. Bay1, P. A. F. Martins2, T. Lenau1
1Technical University of Denmark, Department of Manufacturing Engineering and
Management, DTU - Building 425, DK-2800, Kgs. Lyngby, Denmark
2 IDMEC, Instituto Superior Tecnico, TULisbon, Av. Rovisco Pais, 1049-001 Lisboa,
Keywords: Incremental forming, dummy plate, double plate, multi plate, wear, surface
quality, roughness, bulging and friction.
A new version of single point incremental forming (SPIF) is presented. This version
uses a dummy plate on top of the plate which is to be formed into a geometry.
In this way two plates are formed instead of one. The top plate in contact with
the rotating tool pin is a dummy plate, and can be discarded after forming. The
use of such a dummy plate causes a number of changes in the process. It also offers
the manufacturer a number of new possibilities for solving some of the remaining
problems in SPIF. A hyperboloid and a truncated pyramid are used to investigate
influence of using a dummy plate on: formability, wear, surface quality and bulging
of planar sides. It is furthermore investigated whether the level of friction
between the two plates plays a role. Use of a dummy plate reduces wear to a level
close to zero, but also causes a decrease in formability. Bulging of the planar
sides of the pyramid is reduced 10%. Surface roughness is increased. Use of lubrication
or not between sheets does not have any influence. Suggestions for use of this
new technique are discussed, among those forming of soft aluminum plates thicker
than 1 mm.