Deformation Behavior of Sintered Fe-C-Mn Composite During Cold Upset Forming

Experimental investigations were undertaken in order to understand the mechanism of deformation and densification behavior during cold upset forming operation on sintered Fe-C-Mn composite preforms of two initial aspect ratios 0.45 and 0.60. The preforms were prepared out of mixed elemental powders of Fe, C (0.05, 0.10, 0.15, and 0.20 %), and Mn (0.20 %) and compacted by 1 MN Universal Testing Machine with pressure of 1.1 GPa and then sintered in electrical muffle furnace for an hour and followed by cooling to room temperature in the furnace itself. The material properties of sintered Fe-C-Mn composite preforms were ascertained from the uniaxial compression test. Deformation experiments were carried out in several steps. Analysis of the experimental data showed an increasing trend in the attained density ratio with respect to the strain factor. Preforms having lower aspect ratio had enhanced densification qualities, compared to preforms possessing higher aspect ratio for any given initial preform density. The instantaneous Poisson's ratio with respect to the density ratio attained three distinct stages and approaches to the value of 0.50 of Poisson's ratio. Also an attempt has been made to find the relation between axial stress and axial strain with different aspect ratios and different percentage of carbon content.