Numerical and experimental studies on the effect of varied pulse energy in Nd:YAG laser welding of Monel 400 sheets

The digressions in microstructure and mechanical properties of 600 W pulsed Nd:YAG laser welded Monel 400 alloy sheets, subjected to varied pulse energies (8-12 J) are reported. The influence of pulse energy on the weld morphology is determined and correlated with the numerical simulation by employing finite element software 'Visual weld 8.5′. The peak temperature, width of the weld and the size of the heat affected zone (HAZ) increase with the pulse energy, owing to the enhanced heat input (laser power/welding speed). Weld zone microstructure reveals the formation of fine dendritic grains. Maximum hardness and tensile strength were obtained for the pulse energy of 10 J and the tensile fracture shows a ductile fracture mode for all the attempted conditions.