Correlation between Microstructure and Bending of FSW and TIG Welded Mg-Rich Aluminium Alloy Joints

Abstract

This paper reports on the mechanical properties in relation to the microstructure of the Mg-rich aluminium alloy joints fabricated through friction stir welding (FSW) and tungsten inert gas (TIG) welding techniques. The microstructure, tensile, and bending tests were conducted on friction stir, and TIG welded joints. Most coarse grains (27.81mm) dominated the joint produced using the TIG welding technique, while the refined grains (11.26 mm) mostly dominated the joint made through the FSW technique. The ultimate tensile strength (UTS) of the joint fabricated using the FSW technique was higher (379 MPa) compared to the TIG-welded joint (260 MPa). However, the inverse behaviour was observed when looking at the tensile elongation of the very same joints. The bending results correlated with UTS results, and this phenomenon was attributed to the microstructural grain size.