Influence of GMAW welding parameters on grain size, precipitates, and hardness in alloy 6063-T5

Abstract This article presents a study on the influence of welding parameters, such as power (W), current (A), and weld bevel spacing (mm), on the grain size of the weld bead, the size of the precipitates measured using a SEM microscope, and the hardness measured in the weld bead. The experiments were conducted using the orthogonal Taguchi methodology with an L9 design, meaning 9 experiments. The objective of the optimization is to determine the most suitable values to achieve the best mechanical properties in the welded joint. Power is the variable with the greatest weight and should be kept as low as possible. Bevel spacing is the next most significant variable, while welding speed is the variable with the least weight and should be kept as high as possible. As a practical application, this paper highlights the influence of welding parameters on precipitates and how these relate to hardness, making this a reference parameter for mechanical properties.