MICROSTRUCTURAL ANALYSIS AND MECHANICAL PROPERTIES OF THREE-LAYERED STACK OF FSAM AA7075-CU ALLOYS

Abstract

Friction Stir Additive Manufacturing (FSAM) is a novel solid-state technique which is performed on the basis of Friction Stir Welding (FSW) process. Compared with conventional fusion welding, FSW overcomes welding defects when it is used for joining dissimilar metals. In this study, Friction Stir Additive Manufactured AA7075-Cu alloy is performed on the principle of FSW by which the materials are not melted during the process. The FSW process is performed on the three-layered stack of alloy combinations of AA7075-Cu alloys. The input process parameters, such as axial load, welding feed and rotational speed at different levels, are considered. The effect of mechanical properties, such as microhardness, Ultimate Tensile Strength (UTS) and % elongation, is observed. The microstructure on the welded nugget zone is obtained using Scanning Electron Microscope (SEM). The microhardness of FSAM AA7075-Cu alloys is significantly increased when compared to the microhardness of AA7075 and Cu alloys. The crystalline structure on the welded nugget zone is observed on the microstructure of FSAM AA7075-Cu alloys from SEM microstructures of parent zone as well as welded zone.