Elasto-Plastic Finite Element Analysis of Hydrostatic Extrusion with Various Mathematically Contoured Dies

Summary

The contour of die wall influences on the plastic stress and flow field of hydrostatic extrusion. At present, conic wall die is mostly used. However when it is used to extrude brittle metals, defects are often found on the products. In order to investigate the cause, the stress field and flow pattern of hydrostatic extrusion with dies of equal strain rate, sine curve, Richmond curve, conic and elliptic curve have been computed and studied by elasto-plastic finite element method. Results show that extrusion with die of equal strain rate has the most uniform stress and strain field as well as the less extrusion pressure and tensile stress. It seems that die curve of this kind is the best contour for extruding brittle metals.