Materials Today Communications 36 (2023) 106838 Available online 7 August 2023 2352-4928/© 2023 Elsevier Ltd. All rights reserved. A multi-criterion optimization of mechanical properties and sustainability performance in friction stir welding of 6061-T6 AA Eyob Messele Sefene a, b, *, 1 , Yueh-Hsun Tsai a , Muhammad Jamil c , Vijaykumar S. Jatti d , Akshansh Mishra e , Assefa AsmareTsegaw b , Erick Cardoso Costa f a Department of Mechanical Engineering, National Taiwan University of Science and Technology, No. 43, Section 4, Keelung Rd., Taipei 106, Taiwan b Faculty of Mechanical and Industrial Engineering, Bahir Dar Institute of Technology, Bahir Dar University, P.O. Box 26, Bahir Dar, Ethiopia c College of Mechanical and Electrical Engineering, Nanjing University of Aeronautics and Astronautics (NUAA), Nanjing China d Department of Mechanical Engineering, Symbiosis Institute of Technology, Pune, India e School of Industrial and Information Engineering, Politecnico Di Milano, Milan, Italy f Precision Engineering Laboratory, Department of Mechanical Engineering, Universidade Federal de Santa Catarina, Florian´ opolis, Brazil A R T I C L E INFO Keywords: Friction Stir Welding Taguchi based GRA Sustainable metrics Mechanical properties ARIMA 6061 AA ABSTRACT Nowadays, the transportation industry is curious about fabricating lightweight vehicles under a sustainable manufacturing process to minimize fuel consumption costs and environmental footprints. Assessing the sus- tainability performance metrics of the friction stir welding (FSW) process reduces the sawing costs and envi- ronmental impacts. However, the evaluation and assessment of the sustainability performance metrics integrated with the mechanical properties of the weld joint have not been suffciently studied. Thus, this study investigates the multi-criterion process parameter optimization of friction stir welding (FSW) to attain an optimum parameter to enhance the mechanical properties of the weld joint and decrease energy consumption and carbon dioxide emission. Experimentations are conducted using a vertical CNC milling machine on a 5 mm 6061-T6 AA material with a butt joint orientation. Tool rotational speed, traverse speed, and tool profle were used as processing parameters. Response of the study, such as transient temperature and energy consumption, was measured during the joining process, whereas hardness, tensile strength, and CO 2 emission were examined post-processing. The multi-criterion optimization was done using the Taguchi-based grey relational analysis method. In addition, the transient temperature was predicted by an auto-regressive moving average (ARIMA) and Ansys simulation. The fnding showed that higher rotational and minimum welding speeds had imparted a sound weld. Besides, the analysis of variance results showed that welding speed has a signifcant parameter at a 95% confdence interval. The proposed ARIMA model’s result showed that the transient temperature prediction accuracy reached 99.922%, and the error percentage between the FEA simulation and experimental work reached 2.067%. 1. Introduction The manufacturing industry is a signifcant consumer of materials and energy. Improving the effciency of material and energy usage in manufacturing not only lowers costs but also minimizes environmental consequences. When determining how to manufacture a component, it is crucial to consider not only the cost of the fnal product but also the environmental impact associated with the manufacturing process [1]. Sustainable manufacturing involves utilizing fewer resources, particu- larly energy, and materials, in an environmentally friendly manner that is safe for operators and consumers. It aims to minimize the negative impacts on the environment and society throughout the life cycle of a product [2]. Manufacturing sustainability relies on three key pillars: economic, environmental, and social. Three essential steps are involved in achieving sustainable manufacturing. The frst step involves careful selection of the materials. The second step is to ensure that the chosen manufacturing process aligns with sustainability principles. Finally, the third step entails performing machining operations in a sustainable manner. Fig. 1 illustrates the pillars of sustainable manufacturing and the sequential steps towards achieving sustainability [3–5]. Currently, * Corresponding author at: Department of Mechanical Engineering, National Taiwan University of Science and Technology, No. 43, Section 4, Keelung Rd., Taipei 106, Taiwan. E-mail address: eyobsmart27@gmail.com (E.M. Sefene). 1 0000-0003-4660-6262 Contents lists available at ScienceDirect Materials Today Communications journal homepage: www.elsevier.com/locate/mtcomm https://doi.org/10.1016/j.mtcomm.2023.106838 Received 26 May 2023; Received in revised form 30 July 2023; Accepted 6 August 2023