Study of the effect of laser beam welding on joint of Nimonic 80A superalloy: an experimental approach

The present experimental study investigates the characteristics of a 1.2 mm thin sheet of Nimonic 80A superalloy. This material has been selected for CO₂ laser welding (LBW) view being extensively used in aero-engine components like blades, rings, and discs. Welding parameters of laser power 1400 watts, welding speed 1200 mm/min, and 70 J/mm heat input are considered values for study. All experiments are conducted at ambient temperature. Numerous mechanical tests were executed, including tensile strength and Vickers hardness tests. Tensile results revealed a mean strength of 710 MPa, with yield and ultimate strengths at 881 MPa. Vickers hardness increased gradually from the fusion zone’s centerline towards the base metal, with a minimum of 280 HV at the fusion zone’s centerline. Metallurgical features were assessed using field emission scanning electron microscopes, optical microscopes, and X-ray diffraction instruments. X-ray diffraction indicated identical phases in the fusion zone, heat-affected zone, and base metal. Scanning electron microscopy was used for cross-sectional analysis of the weld joint.