COMPARATIVE ANALYSIS AND OPTIMIZATION OF FRICTION STIR WELDING PARAMETERS FOR AA6351 ALUMINUM ALLOY: AN APPROACH USING AgNO3 NANO COATINGS

Abstract

Friction Stir Welding (FSW) is a solid-state joining process that is widely utilized for aluminum alloys due to its superior mechanical properties and efficiency in aerospace and structural applications. This study investigates the impact of key FSW process parameters on the weld quality of AA6351 aluminum alloy, with and without silver nitrate (AgNO₃) Nano coating. The primary objective is to determine the optimal welding conditions that enhance tensile strength, hardness, and fatigue resistance using the Taguchi L27 experimental design. The experiments were conducted with, perhaps the highest welding speed reported, so far. Through the analysis, optimum combinations of the parameters were suggested for each material at a high speed friction stir window. The selected parameters were tool rotational speed, welding speed, and tool pin profile, each evaluated at three distinct levels. AgNO3 Nano coatings were applied to a set of samples to assess its impact on the welds. The welded samples were then subjected to a series of tests, including tensile strength testing, hardness measurement, and microstructural analysis using optical microscopy and scanning electron microscopy (SEM). This study also investigates the optimization of FSW parameters for AA6351 aluminum alloy using AgNO3 coated nanoparticles as coatings. Mechanical properties were evaluated through tensile tests, hardness measurements, and fatigue tests. Experiments were conducted by welding AA6351 aluminum alloy plates under varying process conditions.