Abstract

This talk presents experimental results and finite element analysis of hot upsetting of titanium alloys Ti64 and Ti407 using three alternative thermomechanical testing systems, Dilatometer DIL805A /T/D, Gleeble 3500, and Servotest TMTS . All samples showed barrelling, as a consequence of an inhomogeneous temperature distribution and friction. The FE model incorporated a full thermal model of the test calibrated using multiple thermocouples. At each nominal temperature and strain-rate, the difference between the FE input constitutive response and the predicted test output is used to correct the experimental true flow stress-strain curves. The analysis applies new procedures for: (i) finding the correction for inhomogeneity using literature data as input to the FE analysis; (ii) smoothing the constitutive data. The corrected model predicts the distribution of local deformation conditions, for application in interpretation of microstructure and texture evolution. This highlights the difference between nominal and actual test conditions, with the central strain and strain-rate being magnified by factors of 2–3.