Analysis of compressibility behavior and development of a plastic yield model for uniaxial die compaction of sponge titanium powder

Uniaxial die compaction of Sponge Ti with a maximum particle size of 3 mm and irregular spongy particle morphology was conducted with the Gleeble® 3500 thermal-mechanical simulation testing system at room temperature. The compressibility behavior of the powder was studied using the Heckel equation. It was observed that the behavior of the material could be analyzed in two compaction pressure regimes. In the low pressure regime (<100 MPa) the powder exhibited high compressibility, while; in the high pressure regime (>100 MPa) lower compressibility of the Sponge Ti was observed. A pressure-dependent plastic yield model was employed to develop the yield criterion of the powder. In this model both geometric hardening of the powder and strain hardening of the incompressible material was considered. The model was validated by comparing the experimental and modeled results.