2019 Volume 66 Issue 8 Pages 405-412
Powder metallurgy, PM method is one suitable method to produce metal parts with high accuracy and high cost performance. Powder compaction process using closed-die system is applied to mass production of various PM parts. However, failure of green compact during compaction such as slip clack often occurs especially on multi step parts. Finite Element Method (FEM) analysis is effective to predict such crack occurrence. In this study, we have tried to simulate iron powder compaction process by using general purpose FEM software ANSYS by applying Drucker-Prager Cap (DPC) Model as yield criterion for metal powder. Three kind of experiment, Uniaxial failure test, Single shear test and Lateral force measurement test was suggested to estimate initial and subsequent yield surfaces of the powder. As result, the materials input parameters for DPC model have been successfully identified as the FEM analysis fairly predicts density distribution of hollow shape with inner flange on several loading pass of the tools. Moreover, it is determined that the crack at the inner flange corner occurs in case of inappropriate loading pass as an intersection of stress state pass with shear failure yield line.