Investigation of process parameters for T-joint aluminum alloy ۶۰۶۱-T۶ with nanocomposites material friction stir welding based on the Taguchi method

Surface layer in many engineering applications is strengthened by ceramic grains where the main parts have higher structure toughness than the original material. This paper presents the effect of four process parameters that have been taken into consideration using Taguchi technique based on L۹ orthogonal array. These parameters are;۱) transverse speed, ۲) type of nano- powders, ۳) rotational speed, and ۴) groove’s depth friction stir welding T-joints aluminum alloy ۶۰۶۱-T۶. This work combines welding T-joint sections and creating MMNCs in welding region simultaneously. The predicted optimum parameters and their percentage of contribution are estimated, utilizing the analysis of variance and signal to noise ratio techniques, depending on tensile test in skin and stringers direction, and hardness test of the joint. Optical microscope and scanning electron microscope (SEM) analysis are used to verify the microstructure and dispersion of nano-powders in welding joint. The best ultimate tensile stress (UTSskin) equal to (۱۷۷MPa) for the skin welded part was obtained at the optimal conditions of ۱۵۵۰rpm rotational speed, ۱۵mm/min transverse speed, Al۲O۳ type of powder and ۱mm groove’s depth. SEM micrographic for metal matrix nanocomposite of all nine experiments revealed that the nano-particles are irregularly dispersed in nugget zone due to one pass. The rotational speeds of ۹۶۰rpm, the transverse speed of ۱۵mm/min, type of powder TiO۲, and groove’s depth of ۱.۵mm, give the greatest hardness value of ۸۰HV in nugget zone. The analysis of variance shows that the groove’s depth is the most significant parameter in this investigation.

Keywords:

FSW technology , T–joint welding , AA۶۰۶۱–T۶ aluminum alloy , Taguchi methods , Nanocomposite