Friction control for accurate cold forged parts

An oscillating ram movement can be used to reduce friction and thereby forming forces in cold forging. This effect is attributed to the rebuilding of the lubricating film during back stroke. A corresponding motion control also affects the final partʹs geometry and enables a reaction to uncertainties like the actual semi-finished product properties. Based on numerical and experimental investigations the paper discusses the potentials and prerequisites of this kind of closed-loop control of the final partʹs geometry.