Design and Fabrication of Friction Stir Welding Setup on Conventional Milling Machine to Join and Characterize AA 6023T6 alloy sheet

Abstract

Friction stir welding (FSW) is a solid-state welding process and invented for joining of nonferrous materials specifically for aluminum alloys only, now it extended to ferrous materials also. It is running for the last two decades and developed from small scale level to high scale level of manufacturing industries by its own advantages over other conventional joining processes. This process has many process parameters in which tool geometry, rotational speed, welding speed, tilt angle etc., are the major ones. Many of the researchers evaluated and examined in an elaborate manner on the effect of process parameters on mechanical and microstructural properties of aluminum alloy welded joints. All the joints were made on Universal milling machine to friction stir welding (FSW) or on the FSW machine itself with different joint configurations. This thesis work carried out on manufacturing adjustable friction stir welding setup on a convectional vertical milling machine and FSW tool to characterize the weld joint of AA 6023-T6. The result show that AA 6023-T6 welded joints using FSW on universal milling machines grain refinement in the weld joint and defects free at optimized parameters of 2000 rpm rotational speed, 12.5 mm/min welding speed and 3˚ tilting angle. The reduction of pin length is 1 mm (reduced from 1.8 mm to 0.8 mm length) and the diameter of the pin/probe increased by 2.3 mm (increased from 3.8 mm to 6.1 mm) is observed. For welded joint hardness performance both the rotational speed and welding speed have significant influence, but tilting angle has insignificant influence on weld joint of FSW of AA 6023 T6. The hardness value has been noted as 53.63 HV that is 99.26 % of base metal hardness. For weld joint strength performance value, the rotational speed has significant influence and both welding speed and tilting angle have insignificant influence on weld joint of FSW of AA 6023 T6. The Optimized parameters tensile strength has been recorded as 194.67 MPa that is 92.70 % of base material. Rotational speed has great effect on weld joint and other parameters welding speed and tilting angle of the tool takes the second and third rank respectively.