Evaluation of a new FEM criterion for seam welds quality prediction in aluminum extruded profiles

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.