The study is concerned with the analysis of combined forging of non-axisymmetric shapes with inclined protrusions by UBET technique. Work hardening is considered for the given range of strain rate during the forging process. A complex shape with inclined cavities is analyzed by subdividing the workpiece into finite UBET elements for which simple velocity fields are applicable.
An experimental set-up was designed and manufactured for the experiment, and experiments are carried out with lead billets. The devised set-up can be used for closed-die forging of complex shapes with protrusions in which the dies can be separated automatically for easy removal of the forged products. Based on the derived kinematically admissible velocity fields for corresponding UBET elements, general computer programs have been developed.
Since the energy dissipation rate for each elemental region is provided by subprograms (Subroutine or Function), the developed program can be applied to the forging problems of various shapes.
It is shown that there are good agreements in forging load and backward extruded length between theory and experiment and the comparison showed the prediction of flow length in the protrusion is in reasonable agreement with the experiment. The discrepancy in flow length is considered to be due to the assumptions made in the analysis.
The theoretical and experimental results showed that the size of a punch has a more sensitive influence on the flow into the cavity than the inclination angle of the cavity and that the design of a punch should be elaborated for proper die filling of material.
The present study has shown that the method developed can be effectively applied to forging of non-axisymmetric shapes with complicated protrusions.
