International Journal of Innovative Technology and Exploring Engineering (IJITEE) ISSN: 2278-3075, Volume-9 Issue-4, February 2020 1581 Published By: Blue Eyes Intelligence Engineering & Sciences Publication Retrieval Number: D1805029420/2020©BEIESP DOI: 10.35940/ijitee.D1805.029420 An Assessment of Non Consumable Welded Joint- Friction Stir Spot Welding C. Labesh Kumar, G. Bharathiraja Abstract: Friction stir spot welding (FSSW) is a pressure weldingprocess where the workpieces are operated below their melting points. FSSW is one of the processes derived from Friction Stir Welding (FSW) Technology. Friction stir welding was invented by The Welding Institute (TWI) in 1991 and proven experimentally. FSSW is found to be environment friendly and a very efficient process. This process is rapidly growing and is replacing the resistance spot welding. FSSW have various applications which include industries like automobile, aerospace, ship building, construction and electrical.FSSW has been successfullyused to join several materials used in the above mentioned industries. Inthis review, FSSW studies are briefly summarised in terms different parameters for joining processes. Keywords: FSSW, FSW, construction and electrical. I. INTRODUCTION Friction Stir Welding (FSW) process was invented and experimentally proven by The Welding Institute (TWI) in 1991 for joining Aluminium alloys [1]. Friction Stir Spot Welding (FSSW) is a variant of the FSW which is found to be environmental friendly and an efficient process. It is majorly used for difficult to weld sheets for lap joints [3]. In this process two work pieces are joined using a non- consumable tool which rotates at a certain speed. The rotating tool is plunged into the workpieces for a predetermined time which is referred as dwell time. After dwell time the tool is retracted from the workpieces leave the Friction stir spot weld. During Friction Stir Spot Welding (FSSW), the plunge depth and dwell time determines the heat generation, amount of material plasticized and mechanical properties of the joint formed [2]. FSSW PROCESS The process mainly consists of three segments plunging, stirring and retracting or drawing out. The tool is driven by a motor attached to the spindle. The tool is rotated at speed range of 1000rpm to 2000rpm. The tool is brought in contact with the workpiece, as the tool is in contact with the tool due to the friction between the tool and workpiece heat is generated. Fig-1: Plunging, Stirring, Drawing out Due to the heat generated the workpiece material is plasticized (softened) and load is applied on the tool spindle which results in the penetration of the work piece by the tool. This process of penetration of the rotating tool into the workpiece is called plunging. The rotating tool then stirs the softened metal till it is in contact with the workpiece, this called stirring. After a while the tool is retracted from the workpiece leaving the two plates (workpiece) welded. Revised Manuscript Received on February 3, 2020. C. Labesh Kumar, Assistant Professor, Department of Mechanical Engineering, Institute of Aeronautical Engineering, Dundigal Village, Hyderabad, India. G. Bharathiraja, Associate professor, Department of Mechanical Engineering, Saveetha School of Engineering, Saveetha Institute of Medical and Technical Sciences, Chennai, Tamil Nadu, India. This process is becoming so efficient that it is replacing the resistance spot welding enhancing the strength, efficient and properties of the joints. The Friction Stir Spot Welding has a wide range of applications in the automobile, aerospace, electrical and construction sectors. 1. PROCESS PARAMETERS There are three main process parameters which are tool rotational speed, plunge depth and dwell time. 1.1. Tool rotational speed The tool rotational speed plays vital role in the process. The profiled tool rotates at a certain speed at around 1000 rpm to 2000 rpm [1].