Correlation between heat generation and mechanical properties in friction stir welding

Abstract

This article presents the correlation between temperature profile and mechanical properties of the friction stir welded 6061 aluminium alloys. The four different tool pin profile, tool rotation speed and welding speed are input process parameters. The temperature distribution along the thickness of the work piece have been analysed by computational fluid dynamics (CFD) and mechanical properties of the weld joint such as ultimate tensile strength, fracture behaviour and weld zone grain size are analysed by experimental techniques. The correlation results show that the peak temperature affects the mechanical properties of the welded work piece material. Tool rotational speed is highly significant factor. The generated peak temperature between 70 and 90% of the work piece solidus temperature gives better mechanical properties for all tool pin profile at the moderate tool rotation speed. The stepped-conical pin profile tool produced maximum peak temperature which shows optimum mechanical properties among all tools.