An analysis of die filling in a forging operation

Abstract

Abstract

The nature and type of flow which occurs when metal is deformed within a closed die has a direct bearing on the loads required to form the metal and the resulting stresses within both workpiece and die. In this paper an analysis of the metal flow which occurs during a non-steady plane-strain closed-die forging operation is investigated with the aid of a version of the well established visioplasticity method. The strain components resulting from an analysis of a deformed grid pattern are used to indicate directions of maximum shear strain. These maximum shear strain directions are then used to suggest possible slip-line fields at various stages of deformation. The results clearly indicate the nature and extent of the metal flow during the final stages of the closed die forging operation. The values of forging pressure based on the computer aided slip-line field analysis is shown to be in good agreement with the experimental results. The use of a micro computer in conjuction with established stress analsysis techniques, such as the visioplasticity method and slip-line field analysis, is shown to provide additional flexibility and accuracy in the use of these techniques.