In this research article, the mechanical properties and microstructure analysis ofFriction Stir Welded (FSW) of dissimilar aluminium alloys AA8011-AA6082 were evaluated. The FSW tool with taper cylindrical shape of H13 steel was selected to fabricate the weld joints between the dissimilar alloys. In this regard, three different rotational speed tools, three welding speeds and an unvarying axial load of 7 kN are used in this investigation. The tool rotational speeds are 800 rpm, 1000 rpm and 1200 rpm. The tool travelling speeds are 25mm/min, 30 mm/min and 35 mm/min. These constraints are used to generate frictional heat and interface into the soft range where the joining process can take place between the two materials. The mechanical tests were carried out on the weld joints. Microstructure analysis, tensile and hardness tests were considered by changing the tool rotating speed, welding speed and maintaining a constant axial force during material joining process. The micro hardness of the FSW weld joints in the stir zone increased to increase the tool rotational speed as well as to maintain a low range of welding speed during material joining process. The micro hardness of the stir zone in the FSW weld joints is increased as to reduce the welding speed. It was found that the highest value of the tensile strength in the joints is made-up of using the taper-shaped tool at 800 rpm, welding speed of 35mm/min and unvarying downward force of 7kN. These identified parameters give sufficient mechanical properties and fewer defects in weld joints such as tensile strength of 68 N and micro hardness of 42 Hv. The tensile and hardness tests values are examined by the part of mechanical characterization and the values are correlated to recognize the superiority of the weld joint.

No abstract

In this research, microstructural events and mechanical behaviors in dissimilar friction stir welding (FSW) of aluminium (Al) alloy AA6082-AA7075 joints have been evaluated to apply aerospace, defense, and military sectors. FSW parametric effects have a more significant impact on the mechanical performances and microstructure of produced joints. FSW tool rotational speed, welding speed, and tool plunge speed were chosen to make the weld joints. The rotational tool speeds of 1600 rpm and 2300 rpm, welding speeds of 40 mm/min and 60 mm/min, and tool plunge speeds of 20 mm/min and 30 mm/min were set as the upper and lower limits. A constant axial force of 5 kN was maintained throughout the joint fabrication process. A taper pin-profiled tool was utilized to produce the butt welded joints. Mechanical properties of microhardness, tensile strength, yield strength, elongation, and bending strength of the joints were analyzed. The response of the stir zone microstructure to processing parameters was evaluated using optical microscopy (OM) and fractographic analysis of a tensile specimen shown by scanning electron microscope (SEM). The weld joints produced at 2300 rpm, tool traveling rate of 40 mm/min, and tool plunge speed of 30 mm/min showed the greatest tensile strength of the 191 MPa hardness of 145 Hv at the weld center and also the maximum bending strength of 114.23 N/mm2 was achieved. The lowest bending strength of 25.38 N/mm2 was obtained at 1600 rpm with 60 mm/min due to inappropriate mixing of the base metals and poor joint quality. Furthermore, this study revealed that a higher tool plunge speed facilitates the formation of equiaxed grains in the thermomechanically affected zone (TMAZ) on the advancing side (AS). Additionally, the increment in tool rotational speed significantly improved the tensile strength, weld joint quality, and joint efficiency.

No abstract

In this work, low-carbon steel AISI-SAE grade 1010 with copper grade CDA 101 was joined by friction stir welding (FSW) using a tapered pin profiled tool. The rotational speed of the tool is 900 rpm, a traverse rate of 30 mm/min, and an axial force of 5 kN were used to produce the joints. The microstructural analysis and mechanical properties of the weld joints have been successfully examined. The optical microscopy, scanning electron microscopy, and X-ray diffraction (XRD) techniques were performed to examine the macropatterns and micropatterns of the welded joints. The tensile and hardness test was performed to evaluate the mechanical behaviours of the FSW joints. The fine ferrite grain features with uniform size were obtained in the microstructure of the nugget zone (stir zone). It is purely influenced by the alternating dynamic rearrangement (recrystallization) mechanism. High hardness was identified in the stir zone, even as the slightest stability was established in the heat-affected zone. The tensile investigation proposed that all the joints explored just lesser unbending nature than the parent material. The tensile strength of 181.5 MPa, the hardness of 144 VHN, and elongation of 14.03% were observed for the welded samples. The better properties for the weld joints were attained at 900 rpm spindle speed and tool traverse speed of 30 mm/min. The FSW is an attractive material joining process for both similar and dissimilar materials compared to other conventional types of joining processes, such as aerospace, marine engineering, shipbuilding, and industrial sector applications.