Abstract
In order to clarify deformation and densification behaviors of porous preforms in sinterforging, effects of preform density, forging temperature and forging pressure on the cracking and densification were investigated, using Fe-0.5C powder preforms.
In hot upsetting between two flat dies, there was no significant difference in deformation behavior between powder preforms and wrought steel billets, except that the former showed the tendency to crack at lower strain. Mean density of the sinterforged specimens increased with increasing preform density and forging temperature. Density distribution in the sinterforged specimen was quantitatively obtained by means of X-ray photoanalysis. In case of hot upsetting, the densification of the specimen proceeded from the core where punch pressure was high and also lateral' material flow was large. Density distribution was made to be more homogeneous by reducing the cooling effect of the die. In hot repressing, it was observed that the densification proceeded from the upper part of the specimen.
