In recent years, sintered compacts have been attracting attention in the field of automotive parts manufacturing. However, it has been reported that the mechanical properties of sintered compacts are inferior due to internal microporous and surface defects. To solve this problem, a processing process to increase the density of sintered compacts by cold forging has been investigated. The purpose of this study is to construct a finite element method (FEM) analysis of the powder molding and subsequent cold forging of a simple iron-based sintered body that simulates a part subjected to locally high loads. A floating die method was adopted for compaction. After powder compaction, the compacts were primary sintered and cold forged. The load-stroke diagram obtained from the cylindrical powder compaction experiment was then used to create a true stress-true strain diagram considering the density change. The analysis of the powder compaction and cold forging using the prepared true stress-true strain diagram showed that the load-stroke diagram and the relative density distribution in the surface region agreed with the experimental results. A three-dimensional analysis was also performed, taking into account the elastic deformation of the die.
IGUCHI et al. (Wed,) studied this question.