Plane-strain coining

Abstract

The forces and stresses associated with the final stages of die-corner fillout during a closed-die forging operation are difficult to predict. This problem was investigated for the forging of high-conductivity copper under plane-strain conditions, using an upper-bound method. The choice of suitable deforming regions and the most appropriate velocity fields for these regions was made with the aid of the visioplasticity technique. Theoretical results based on the upper-bound solutions were found to be in close agreement with the results of a series of forging experiments. A simplified upper-bound expression was found to give solutions which should be sufficiently accurate for engineering problems.