Friction Stir Welding

Abstract

The friction stir welding (FSW) process is considered a greener welding process. As compared to fusion welding processes, FSW offers many advantages to produce superior-quality welds with excellent mechanical properties. At its inception, the process was considered favorable for welding materials with low melting points like aluminum. Considering the latest needs of the industry, considerable progress has been achieved in the area of friction stir welding of steels. The present chapter aims to present a review based on specific progress that has been achieved in addressing several challenges that occur during friction stir welding of steels, namely tool material, tool geometry, and microstructural and mechanical property changes. The chapter also shows that this technique has wide potential for welding steel structures while attaining excellent mechanical properties. The main fact behind its sustainability lies in the fact that this process can have greater control of phase transformations as compared to the conventional way of welding. The chapter also presents a review of different variants of friction stir welding processes that can lead to a superior quality weld.