Material flow and defect prediction during friction stir welding of an AZ31B alloy using a solid mechanics simulation
By Rafael Arthur Reghine Giorjão (Ohio State University), Julian Ávila (São Paulo State University ), Eduardo Monlevade (São Paulo University), Antonio Ramirez (Ohio State University), André Tschiptschin (São Paulo University)

Friction stir welding of light alloys has increased the number of applications on the aerospace and automotive industries. To date, defect prediction, process parameters, and tool geometry optimization have been conducted using numerous experiments. In this matter, a computational solid mechanics numerical model aimed at simulating the friction stir welding process in an AZ31 alloy is proposed. This model compares two different pin profile tools, with threaded and unthread pins. Real welded plates were conducted with these tools for comparison purposes. The pin with threads generates a downward flow in the material during processing, which is not observed in the unthreaded pin, promoting the void defect formation. A point tracking analysis of the material flow revealed that threads increase the material velocity and strain rate, promoting a temperature increment during the process, which improved the material flow and avoided filling defects.