Electrically Assisted Global Springback Elimination After Single Point Incremental Forming

Abstract

There has been a push in the automotive and aerospace industries towards die-less forming processing that are able to reduce both part cost and part energy. Incremental forming is a die-less forming process that fabricates parts using hemispherical tools following a tool path (similar to that found with conventional milling operations), that slowly deforms the sheet metal into the final desired configuration. Global springback for incremental forming, as defined herein, occurs after the part is unclamped from the retaining fixture. This form of springback is currently a significant impediment to the process since, when the part is released, the residual stresses created during the forming process result in significant part distortion and thereby, undesirable part geometries. To reduce this issue, this paper examines the effect on direct electric current on residual stress and springback elimination when applied post forming, which previous work has shown the potential to reduce this issue. This work is an extension of previous work resented at MSEC 2015. The previous work examined applying electric current to areas of high residual stress through the material’s thickness. This work examines the effect of applying electric current along the length and width of a part (path testing). This work concludes that running multiple paths increases springback reduction and the order in which the path testing is conducted has very little appreciable effect on the springback reduction during path testing.