Effect of Process Parameters & Tool Geometries on Properties of Friction Stir Spot Welds: A Review

Friction stir spot welding is the energy efficiency, environment friendly and relatively new low energy technology adopted from Friction stir welding (FSW) with many potential applications in joining light alloys in the automotive industry. In 2001, Friction stir spot welding (FSSW) was developed in the automotive industry to substitute resistance spot welding for aluminum sheets. FSSW process has some advantages such as ease of joining materials, low distortion, excellent mechanical properties, low power consumption, low cost and more economical than RSW. The strength of welds is critical when applying FSSW to load bearing components. This strength is affected mainly by process parameters and tool geometry. Tool geometry, such as shoulder diameter and shape, pin shape, length, diameter and feature is a key parameter to affect heat generation and material flow. The objective of this paper is to review open literature sources to assess the current state-of-the-art developments in Friction Stir Spot Welding, effect of various welding variables like tool rotation, transverse speed, dwell time, tool tilt, plunge depth and tool design on mechanical properties in the welding of aluminium alloys or various dissimilar alloys. However the Literature review indicates that there is need to identify the effect of different process parameters on Mechanical properties in FSSW.