Abstract
Aluminum alloy AA8011 is widely utilized in automotive and lightweight engineering applications, although traditional fusion welding frequently produces faults due to its high thermal conductivity and restricted weldability. This work investigates High Power Diode Laser Beam Welding (HPDLBW) of 2 mm AA8011 sheets employing laser power (3.2-3.4 kW), welding speed (17-23 mm/s), shielding gas (20 L/min) and beam diameter (3-4 mm) built with a Taguchi L9 orthogonal array. A response surface model linked process factors to mechanical responses, including impact energy, hardness, and tensile strength. Optimal settings for multi-objective optimization (P = 3.3 kW, v = 17 mm/s, d = 3.5 mm) resulted in 110 J of impact energy, 33 HV0.5 of hardness, and 69 N/mm(2) of tensile strength. Analysis of variance revealed that laser power accounted for up to 38.6% of the variation in weld penetration, confirms its prominent role in melt pool development, while tensile strength improved by a maximum of 14.2% under optimal conditions. Under optimum conditions, microstructural research revealed refined fusion zones, minimized intermetallic formation, and little porosity. The work shows that Taguchi-based modeling and optimization give a predictive framework for enhancing AA8011 weld performance, and it establishes HPDLBW as a dependable method for lightweight alloy joining. The study demonstrates HPDLBW as a viable and scalable joining technology for lightweight aluminum structures, with lower heat input, improved surface polish, and practical significance for the automotive and packing industries.