Numerical Simulation of Metal Powder Compaction Considering Material & Geometrical Nonlinearity

Metal powder compaction is a quite important process in powder metallurgy (PM) industry and it is widely applied in the manufacturing of key components in different fields. The numerical simulation based on the finite element method (FEM) provides a flexible and efficient approach for the researches of this process and its complicated mechanical behaviors. Numerical simulation plays an important role in the intelligent manufacturing technology (IMT) and computer integrated manufacturing system (CIMS). By the aid of FEM, intricate mechanical models can be introduced into a calculation and many parameters can be determined. The work in this paper was based on the assumption that the metal powder system is a kind of compressible continuous material. The ellipsoidal yield criterion and elasto-plastic constitutive relationship correspondent to the mechanical behaviors of powder compaction were analyzed. Considering the geometrical nonlinearity conditions such as large displacement and large strain, the incremental-form constitutive relationship based on the updated Lagrange (U.L.) formulation was derived. And the correlative calculating codes was implemented into the user-subroutine in the MSC.Marc platform. With these codes, three-dimensional elasto-plastic Finite Element (FE) simulations of the compaction processes of a cylindrical sample were performed. The compact force and distribution of the relative density of this sample were analyzed. Numerical simulations provide effective references for the optimization of the tools, processes and its control schemes as well as for the IMT and the development of the devices.