Using finite element simulation to assess the effects of compaction sequence variation and special geometric features on the final compact density

In order to produce crack-free and homogeneous compacts, powder metallurgy engineers often spend tremendous efforts designing compaction tooling as well as tools movement sequence. In order to avoid the traditional and costly "trial and error" approach, the finite element simulation technique has recently been considered as an alternative design tool. A finite element simulation module based on the Cap material model has been developed and experimentally validated. This module is used in this paper to illustrate the effects of compaction sequence variation on the final compact density distribution. The results clearly demonstrate that changing the compaction sequence may totally alter the final density distribution even if the compaction ratio and the amounts of upper and lower compaction are kept constant. Simulations are thus used to determine the best compaction sequence based on a minimum density gradient criteria. Additional simulations featuring complex parts are also presented. The effects of some of these parts geometric features on the final density distribution and on the tools stress level are investigated.