OPTIMIZATION OF PROCESS PARAMETERS FOR CONICAL AND CYLINDRICAL TOOLS WITH GROOVES IN FRICTION STIR WELDING PROCESS

Friction Stir Welding is a recent emerging welding technology invented by The Welding Institute (TWI) in 1991. This has evolved into a process focused on joining of arcweldable (5xxx and 6xxx) and difficult to weld (2xxx and xxx) aluminum alloys. The present study is aimed to determine the optimum process parameters and identify the most influencing significant parameter along with percentage contribution of each parameter on tensile strength of Friction Stir Welded AA 7075–T6 aluminum joints by conducting specific number of experiments using Taguchi approach. In this study, tool pin profiles having conical and cylindrical head with grooves are used. It has been observed that the tool rotational speed exhibits more influence on tensile strength in both the tools. Further the tool having conical profile results in better joint efficiency than the tool having cylindrical profile. The method described in this paper for the prediction of tensile strength and optimization of process parameters can eliminate the need for performing more experiments on the basis of conventional trial and error method.