Some aspects on hot forging features of P/M sintered iron preforms under various stress state conditions

The present investigation involves the evaluation of hot forging features in pure iron sintered preforms. Cylindrical compacts with different aspect ratios were prepared, sintered and forged at the temperature of 1150 °C. This suggests that the experimentally determined theoretical density ratio has a straight line relationship with the new geometrical shape factor ((ρf/ρth)(h0/hf)(3D02/2Db2+Dc2)). The measured barrel radius of curvature is found to have a circular arc. An attempt is made to establish a relationship between the measured barrel radius and the stress ratio parameters namely (σθ/σz), (σz/σm) and (σeff/σz), and Poisson’s ratio in plane and triaxial stress state conditions. The influences of densification which take place during the plastic deformation on various parameters namely the geometrical shape factor, stress ratio parameter and barrel radius have been studied.