Experimental Analysis of Friction Stir Welding Parameters on Aluminium Alloy Joints

Abstract

Friction stir welding (FSW) is a solid-state joining process that is particularly suitable for aluminium alloys because the joint is formed below the melting point, thereby reducing solidification defects associated with fusion welding. This methodology paper presents a compact experimental framework for analysing the influence of tool rotational speed, traverse speed and tool tilt angle on the quality of AA6061-T6 butt joints. A three-factor, three-level Taguchi L9 design is adopted to reduce the number of experimental trials while retaining the ability to compare principal parameter effects. The proposed work uses a hardened H13 steel tool with a cylindrical threaded pin, controlled axial loading, and constant plate thickness. Joint performance is evaluated through visual inspection, tensile testing, Vickers microhardness measurement and optical metallography. Signal-to-noise ratios and analysis of variance are used to identify the parameter combination that maximizes ultimate tensile strength while maintaining adequate hardness and defect-free material flow. The experimental logic is consistent with prior FSW studies showing that rotational and welding speeds strongly influence heat input, nugget formation and tensile behaviour [1–4]. For demonstration of the analysis workflow, an illustrative L9 dataset is included because no laboratory measurements were supplied with the request. The representative trend indicates an intermediate heat-input condition as the most favourable, whereas low or excessive heat input is associated with lower strength. The paper provides a reproducible procedure that can be directly applied to measured laboratory data and supports systematic selection of FSW parameters for lightweight aluminium structures.