The study is concerned with the analysis of spike forging and backward extrusion as nonsteady processes by the rigid-plastic finite element method. These processes include die boundaries of curved shape and this should be taken into account in the finite element formulation. The rigid-plastic finite element formulation. The rigid-plastic finite element formulation is one of the most efficient numerical tools to obtain detailed information including the distribution of stresses and strains in the analysis of metal forming processes.
The spike forging process is characterized by large free surface, rigid part and curved contact surface. The developed program for initial velocity field generation is included in the present FEM program. The workhardening effect, rigid body treatment and interface friction along curved die surface are introduced in the formulation. In backward extrusion deformation is very severe around the punch corner and the remeshing technique is employed in the FEM program to combat this program.
The Experiments are carried out for spike forging and backward extrusion with commercially pure aluminum(Al 1100) billets. Computational results in deformation and load are in excellent agreement with the experimental obserbation. The present analysis permits the prediction of stresses, strains and strain rates. The effects of friction factors on interface pressure and spike height are discussed in spike forging. It is thus shown that the present formulation enables the effective design of axisymmetric cold forging process.
