NUMERICAL ANALYSIS OF POWDER FORGING UNDER VARIOUS INITIAL DENSITY DISTRIBUTIONS AND FRICTION CONDITIONS

摘要

Finite element models have been developed to simulate forging of sintered porous powder metal. The deformation behaviour of the porous preform during hot forging has been described by the Duva and Crow porous material constitutive model. It has been implemented into general purpose nonlinear finite element software within a large deformation formulation. Most of the previous finite element analyses of the deformation of this porous preform always assume an initial homogeneous density distribution within the compacted porous preform. However, the compacted parts obtained after compaction and sintering usually possess inhomogeneous density distribution. The present finite element models therefore take into account the initial distribution of relative density within the preform. The simulations have been conducted for various initial density distributions and under various frictional conditions in order to investigate the deformation characteristics and the evolution of voids in the forging process.