Some aspects of hot axisymmetric upsetting pressure prediction

In this research work, the pressure–deformation curves of hot upsetting of AA 6015 aluminium alloy were measured and compared to curves calculated on the basis of torsion test results. Such tests, performed in the temperature range from 300 to 500°C at strain rates varying from 0.042 to 1.4 s−1, yielded a constitutive equation correlating peak flow stress with temperature compensated strain rate. This equation was used in the calculation of hot upset forming pressures of the same material by means of a relationship derived from the slab method. The pressures predicted by the proposed method, are in good agreement with the experimental results over a wide strain range. Accuracy limits and discrepancies between predicted and experimental data have been analysed and are discussed in detail.