An Extrusion Forging Study with Improved die Geometry

Summary

In the present paper, some experimental results are presented and compared with the output of an FEM code: extrusion forging operations, using dies with fillets and drafts, are investigated. Several geometries of the dies are taken into account both in the presence of lubricant and under dry conditions, when testing annealed copper specimens. The results are expressed in terms of total compressive force and extruded body height, the overall shape of the deformed specimen is measured as well.

An FEM program, developed in the University of Brescia for the study of plastic deformation of axisymmetrical shapes, is used to model the rigid-plastic behaviour (with work-hardening) of the material. Some mathematical problems, arising when dealing with conical surfaces and complex constraint conditions, are presented here. A fairly good agreement between experimental and theoretical results was found for the cases considered. This proves the ability of the software package to simulate extrusion forging processes with the characteristic mentioned above.