Effect of Friction Stir Welding Process Parameters with Interlayer Strip on Microstructural Characterization and Mechanical Properties

Abstract

Process parameters of friction stir welding (FSW) with different values of interlayer strip widths have become a very vital research area to reinforce the weak part of the nugget zone in welded joints. So, the objective of this work is to study the effect of different process parameters of FSW such as the tool rotational speed (R), travel velocity (υ) and inclination angle (Θ) with different values of interlayer strip widths (W) of compensation material on microstructural characterization and mechanical properties. Optical microscope, scanning electron microscope, energy-dispersive x-ray spectroscopy and x-ray diffraction techniques were used to characterize the microstructural changes after FSW process. Microhardness and tensile tests were also used to characterize the mechanical properties of the produced joints. The results of mechanical properties of FSW process parameters with different values of interlayer strip width showed that when the tool rotational speed is increased till 2000 rpm, the tensile strength has been increased till 321 MPa, while the reduction in tool traverse speed till 20 mm/min led to an increase in the tensile strength till 239 MPa. Moreover, the best inclination angle was 2.5°. The microstructure observations revealed that the use of process parameters of FSW at 2000 rpm rotational speed, 20 mm/min traverse velocity and 2.5° inclination angle with different values of interlayer strip width showed excellent connections of reinforcement clusters of AA7075 compensation material between the matrices of AA2024 base metals.