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The paper reports information in term of simulation settings and output results related to the Industrial benchmark 2015 : extrusion benchmark is an event where participants from software houses, industries and academia are re quested to simulate an extrusion process case which main experimental data are initially unknown and disclosed only after the submission of simulati on results.

Aim of t he benchmark is to examine FEM codes capabilities and users’ knowledge in the simulation of extrusion trials which were carried out and monitored by conference organizers. The comparison of the “blind” simulations by the participants with the experimental results allow s users to check if their simulation settings are generally adequate to replicate the problem and soft ware house to verify the sensitivity of their solving methods. It is very important for us to remind that, due to the complexity of this matter, it would be useless to consider the benchmark as a contest: it is, instead, an opportuni ty to fix some points a bout the e veryday simulation practice, each participant wi th his own particular interest . I n this direction no winner will be awarded at the end of the conference because a clear comparison of code’s capabilities will visibly emerge.

In the first part of the work an experimental procedure to investigate the evolution of recrystallization in aluminum alloys is presented and discussed. Several cups, obtained by means of inverse extrusion, were produced at different temperatures and process speeds. The specimens were analyzed in order to examine the grain size distribution. The coefficients for dynamic recrystallization models were obtained by regression analysis after thermo-mechanical FEM simulations of the experiments realized with the code Deform 3D. The specimens were then heated in a furnace and cooled in order to reproduce static recrystallization of the material. The grain distribution was examined and the coefficients for the equation for static recrystallization prediction were regressed, too. In the second part of the work the extrusion of a round-shaped profile is described and the grain size distribution on the profile and on the billet rest are analyzed. The developed equations were applied to the rod extrusion and the simulated grain size distributions were compared with the experimental ones.

The first review and comparison of methods for predicting the quality and strength of seam welds in aluminum extruded profiles is here presented. Inasmuch a general methodology for weld quality prediction has, so far, not been presented, the authors review the existing rules and proposed criteria for sound welds production, rendering them in a form suitable for FEM practice. Then, basing on both original and bibliographical experiments, the material flow fields of a AA6082 aluminum alloy inside the welding chambers are reconstructed by means of complete thermo-mechanical FEM analyses, in order to apply the identified criteria and verify them by evaluating similarities with experimental results. Thus, the reliability and robustness of the applied criteria in a wide range of operative conditions are evaluated and an original criterion for welding quality prediction is eventually proposed, which best fits experimental evidences. An extensive campaign for weld strength evaluation is also performed, by means of tensile tests carried out on the extruded profiles, the results being related to the process parameters of the extrusion.

Charge welds are unavoidable defects of the continuous extrusion process whose extension needs to be accurately predicted in order to avoid profile mechanical failures or to minimize unrequired scrap of material. The aim of this work was then to evaluate the accuracy of the charge welds FEM predictions and their applicability in the industrial field. Two different industrial cases involving A6082 and AA6063 aluminium alloys were analysed. The data of charge welds behaviours were experimentally collected, discussed and then innovatively compared to the predicted outcomes of FEM simulations performed using QForm Extrusion® software and of theoretical formulas reported in the literature. As main results, a very good numerical-experimental matching was found, with a peak discrepancy of 122 mm in terms of charge weld extent, while theoretical formulas returned a significant underestimation.