Finite element analysis of enclosed die forging of axisymmetric parts

In this thesis, the finite element analysis of enclosed die forging of axisymmetric parts is studied. Prediction of the exact behavior of enclosed die forging process is becoming increasingly essential and it also important to optimize the process design to reduce the required load and consumed energy. In this study, evaluation of forging load and metal flow for H-shape part by using various punch/counter-punch movements and various preforms are presented. By using a finite element analysis (FEA), uni-directional forging and bi-directional loading conditions for two types of preforms (upset and extrusion mode of deformation) are compared in terms of forging load, deformation energy and metal flow under different friction conditions. The effects of rib angle and hub thickness of H-shape forgings on the forging load and energy are also shown. The experimental work is carried out by using a modeling material (plasticine) for verification. The results show that the forging load asymptotically increases at the final stage of the forging where the corner filling of the die cavity. The maximum forging load is considerably reduced by using the bi-directional step loading (divided flow), therefore, the usage of servo-driven presses are very effective. The material flow in bi-directional forging of the H-shape is symmetrical while the flow in uni-directional forging is non-symmetrical. The non-uniform material flow increasing the deformation resistance and friction load. Key Words: FEM, enclosed die forging, divided flow, bi-directional loading