Modelling tensile strength of friction stir welded aluminium alloy 1100 using fuzzy logic

Abstract

Friction stir welding (FSW) is a promising technique in which joints with high strength and minimal defects can be realized by adopting optimum process parameters. The prominent parameters are tool rotation speed, welding speed, shoulder diameter and pin diameter of the tool. In this study Mamdani fuzzy system was used to generate the model for predicting and exploring the influence of FSW process parameters on tensile strength of AA1100 joints. The FSW trials are conducted at various levels of process parameters according to central composite design. The study proved that the process parameters had significant effect on the tensile strength of friction stir welded joints. Crest parabolic variation trend was observed in tensile strength of the joints, with respect to the interaction effects of TRS, WS and SD. Increase in pin diameter had positive effect in increasing the tensile strength of the joints, for any change in TRS, WS and SD. Maximum tensile strength of 72.4 MPa was obtained at tool rotation speed of 1050 rpm, welding speed of 60 mm/min, shoulder diameter of 18 mm and pin diameter of 6 mm. The methodology given in this paper delivers a useful tool to assess the tensile strength of friction stir welded AA1100.