Taguchi optimization study on friction stir weld parameters for enhancing dissimilar joint strength of AA8011 and AA5052

The present study attempts to investigate the properties of friction stir welded butt joints constructed of AA8011 and AA5052 aluminum alloys. AA8011, which is composed of aluminum, iron, silicon, and copper, is known for its corrosion resistance, electrical conductivity, formability, and thermal conductivity. AA5052, an aluminum alloy with magnesium and chromium, is noted for its high strength, corrosion resistance, good formability. Friction stir welding (FSW) was chosen as the joining method because of its distinct solid-state approach, which avoids the melting and recasting of materials inherent in fusion welding processes. This method uses frictional heat to bind surfaces without using consumable filler ingredients. A Taguchi optimization of FSW process of two different aluminum alloys, AA8011 and AA5052 by varying tool rotational speed (TRS), feed rate (FR) and tool tilt angle (TTA) was performed. A total of 9 experiments were carried out and responses such as ultimate tensile strength (UTS), Yield Strength (YS), % elongation and hardness were perceived. The investigation revealed that at TRS 840 rpm, feed rate 50 mm/min, and TTA 1°, the highest YS (165.26 MPa) and UTS (192.32 MPa) were recorded. TRS at 560 rpm, FR at 40 mm/min, and TTA at 0° resulted in the lowest percent elongation (11.54%). TRS at 560 rpm, FR at 30 mm/min, and TTA at 2°, the highest hardness (64.91 N/mm²) was recorded. ANOVA results reveal the most effected parameters for UTS, YS, % elongation and hardness. The R² value of the regression models (UTS, YS, %El and hardness) was close to 1, indicating the best correlation can be achieved. The post-tensile specimens’ fracture surface morphology also demonstrated a ductile failure pattern.