Numerical and experimental investigation on AZ91 friction stir welding joints: Mechanics, properties

Abstract

The present endeavour is to evaluate numerically and experimentally the influence of friction stir welding (FSW) parameters on peak temperatures, microstructures and mechanical properties of AZ91 magnesium alloy joints. A full 3D finite element ABAQUS model was developed to simulate the temperature distribution along the joint line. Therefrom, a total of nine different parametric combinations were derived for experimentations. Important insights relating to the material flow patterns and grain morphologies observed while altering the processing parameters have been elaborated. The parametric influence on the peak temperatures, grain morphologies, intermittent phases, tensile strength, and hardness are discussed through several mechanisms. Remarkably, the specimens prepared with the highest tool rotation speeds exhibited superior properties owing to several strengthening mechanisms.