Purpose This paper aims to predict the performance of friction stir welded AA8090 joint. Design/methodology/approach In the present study, Al-Li AA8090 plates are butt joined using friction stir welding (FSW). The experiments are designed and optimized using a Taguchi-orthogonal array. The experiments are conducted at three different process parameters, i.e. tool rotational speed (TRS), tool transverse speed (TTS) and dwell time (DT). The ultimate tensile strength (UTS) and microhardness (MH) are considered as response parameters. In addition, a statistical tool (ANOVA) is used to check the adequacy of experiment results. Findings The maximum UTS of 220 MPa is obtained at a TRS of 1,400 rpm, tool TTS of 40 mm/min and DT of 15 s. The maximum microhardness is obtained for 1,400 rpm, 25 mm/min and 8 s, i.e. 108.6 HV. The microstructural showed that the minimum grain is observed at the nugget zone. Fractography analysis revealed the ductile behaviour of fractured surfaces. Originality/value From the reported literature, it has been observed that very limited work is reported on the FSW of AA8090 alloy. Further, the thermal behaviour of welded joint is also observed in this experimental work.

Purpose This paper aims to accomplish friction stir welding (FSW) of Al–Li alloy AA8090 to determine optimal settings of the process parameters for higher tensile strength and higher micro-hardness (MH) to achieve the objective of adequate butt-joint strength. Design/methodology/approach An empirical relation is implemented to govern the utmost influence parameters, i.e. tool rotation speed (TRS), tool transverse speed (TTS) and dwell time (DT). Taguchi grey relational analysis (GRA) was applied for multi-response optimization of response parameters. The grey relational grades (GRs) have been calculated for both the responses MH and ultimate tensile strength to get optimal parametric settings. The variance test has been performed to check the adequacy of the model. Findings The Taguchi L9 orthogonal array design was used in establishing the relation between input parameter and output parameter (tensile and MH). TTS and DT have been predicted to be the two most important parameters that influence the extreme quality features of joints by using friction stir welding. Scanning electron microscopy fractography shows the ductile failure of the welded joints. Originality/value The experimental trials provided the followings results, maximum ultimate tensile strength (UTS) of 219 MPa and MH 107.1 HV under 1,400 rpm of TRS, 40 mm/min of TTS and 8 s of DT founded the optimum value through GRA.

This paper clarifies the basic standard and procedure of FSW. It consists all the specialized characteristic which influences the procedure and excellence of FSW joint. Effect on every form of joint setup is taken into consideration. All the methodological parts of FSW tool geometry and material of tool is taken. In this article influence of essential parameters like tool rpm, tool feed, tool tilt angle, downward command and tool depression time on joining quality has been calculated. Finally, the fields on which further more exploration can be carried out has been identified.

Purpose This study aims to determine the effect of different friction stir welding (FSW) parameters on mechanical and metallurgical characteristics of aviation-grade AA8090 alloy joints. Design/methodology/approach Response surface methodology with central composite design is used to design experiments. The mechanical and microstructure characteristics of the weld joints have been studied through a standardized method, and the influence of threaded pins on the joint microstructure has also been assessed. Findings From a desirability strategy, the optimum parameters setting of the friction stir welding was the tool rotational speed (TRS) of 800, 1,100 and 1,400 rpm; tool traverse speed (TTS) of 20, 30 and 40 mm/min; and tilt angle 1°, 2° and 3° with different tool pin profiles, i.e. cylindrical threaded (CT), square threaded and triangular threaded (TT), for achieving the maximum tensile strength, yield strength (YTS) and % elongation as an output parameter. The TRS speed was the highest weld joint characteristics influencing parameter. Peak tensile strength (378 MPa), percentage elongation (10.1) and YTS (308 MPa) were observed for the optimized parametric value of TRS-1,400, TTS-40 mm/min and TA (3°) along with CT pin profile. Microstructure study of the welded surface was achieved by using scanning electron microscope of output parameters. When the tool rotation speed, tool transverse speed, tilt angle and tool profile are set to moderately optimal levels, a mixed mode of ductile and brittle fracture has been seen during the microstructure analysis of the welded joint. This has been aided by the material’s plastic deformation and the small cracks surrounding the weld zone. Originality/value From the reported literature, it has been observed that limited work has been reported on aviation-grade AA8090 alloys. Further thermal behavior of welded joints has also been observed in this experimental work.