Effect of Feed Rate in FSW on the Mechanical and Microstructural Properties of AA5754 Joints

Abstract

Friction stir welding is a solid-state welding process, which is successfully applied to aluminum alloys to replace fusion welding processes. In the present work, the influence of varying the feed rate at constant rotational speed on the mechanical and microstructural properties of friction stir welded AA5754 was investigated. FSW caused dynamic recrystallization leading to microstructural changes in different zones. Electron backscattered diffraction confirmed such changes via misorientation angle and subgrain size distributions. Energy dispersive spectroscopy determined the elements present in the matrix quantitatively and their distribution through mapping. Tensile and hardness tests showed slight enhancement compared to base metal. The strain hardening exponent was used to investigate the effect of varying the feed rate on the behavior of the welded samples.