Effect of Different Friction Stir Spot Welding Techniques on the Mechanical Properties and Microstructure of Aluminum AA2024-T3

Abstract

This paper presents a comparison of using different techniques for stir spot welding of Aluminum 2024-T3, which are refill friction stir spot welding (RFSSW), edited (RFSSW-pin) and conventional friction stir spot welding (FSSW), depending on the obtained tensile shear strength property. Specimens were prepared from AA2024-T3 sheet for chemical analysis and mechanical tests. Workpieces were stir spot welded utilizing the above mentioned techniques at four rotational speeds (2000, 2500, 3000 and 4000 rpm) using tool pin diameters (5 and 7 mm) for conducting the tensile shear tests. The microhardness along the cross section of the welded specimens was conducted at the best conditions as well as the microstructure examination. The comparison results revealed that at the rotational speeds (2000 and 4000 rpm) in both cases of tool pin (5 and 7 mm), the ultimate tensile shear force was slightly higher than that for other speeds. However, the ultimate tensile shear force was found higher at 3000 rpm speed with a tool pin 7 mm. The microhardness results manifested a W-shape at the best conditions. Finally, the microstructure examination depicted the morphology of the main zones of the weld joint.

Numerical and Experimental Analyses of Developed Friction Stir Spot Welding (DFSSW) Based on Systematic Design Process Approach

“…The first equation is the heat generation equation, which describes the amount of heat generated during the FSSW process. The heat generation equation is given by [ 21 ] where μ is the coefficient of friction, p is the applied pressure, ω is the angular sliding speed, R Tool is the radius of the too, 3 H Plunge is the depth of plunge, and t is the time. The equation of heat transfer can be written as follows, which describes how the heat is transferred from the tool to the materials being joined [ 22 ]: where k is the material's thermal conductivity, T is the temperature, and ∇ is the Laplacian operator.…”

The Electrical and Mechanical Aspects of Aluminum and Copper Resistance Spot Weld Joints

“…It creates weld nuggets with the desired shape and size, ensuring they can withstand mechanical deformation and provide the necessary toughness. RSW is one of the greatest techniques for sheet metal manufacturing because of its simplicity, flexibility, and ability to offer features in the form of a workpiece [1][2][3][4][5][6][7][8]. RSW is a technique for joining two pieces of metal using an electric current to weld the lap joints in the interface surfaces [1,2,[6][7][8][9][10][11].…”