From Experimental Data an Analytical Model of Powder Behavior During Uniaxial Cold Compaction

In this work the behaviour of ferrous powder during uniaxial compaction was investigated; experiments were carried out in a hydraulic press, producing green parts with different H/D ratio and different density. The data continuously recorded by the press in terms of force and displacement of the axes were analysed, allowing to distinguish the contribution of the reversible phenomena (elastic deformation of powders and tools) and of the irreversible phenomena (rearrangement and plastic deformation of the powders). A preliminary analytical model describing the trend of reversible and permanent deformations of the column of powder versus the applied pressure was proposed. From the analysi s of the data recorded in different compaction cycles, densification curves have also been derived.