Simulative Model for the Feasibility Study and Stress Analysis of Full Dense Rods and Pipes Produced by Friction Stir Extrusion

The Friction Stir Extrusion process is increasingly proving to be a good answer to the growing demand for metal products obtained by limiting the consumption of both energy and raw materials. Indeed, with this technological process, it is possible to obtain axisymmetric extruded components starting directly from metal scraps, which are typically the traditional processing scraps by chip removal. In this work, the feasibility and effects of different process configurations (direct or inverse extrusion) and of different manufactured objects (filled rods or pipes) on the response parameters (stress analysis and global bonding conditions) were investigated. To do this, a finite element simulation model was developed with which it was possible to carry out the thermo-mechanical analysis of the entire process. The results obtained allowed to highlight the potential of Friction Stir Extrusion in both its declinations of direct and inverse extrusion and in the possibility of correctly extruding both full rods and pipes. Furthermore, the technological windows able to determine the optimal combinations of process parameters, according to the achievement of the global bonding conditions, were also identified.