Microstructure and Mechanical Properties of Laser Welding Joint of Inconel 718 Super Thin Sheet

Abstract

Nd-YAG laser welding characteristics of Inconel 718, microstructures,tensile properties,and hardness of welding joint were researched. Nd-YAG laser welding was carried out on super thin Inconel 718 sheet(0.2 mm thick) with 6 specimens. The welding parameters of these specimens are varied expect for the welding speed(0.3mm/s), gas-flow rate (5L/min) and clearance between focal point and (plate) surface(0).In this research,the tensile strength of welding joint was found to be inferior to base metal and the ductility of welds was considerably lower than base material,the microhardness in weld zone is higher than the base material hardness and the hardness is highest in center zone of welding joint. These conclusions will be in favour of the manufacture with super thin Inconel 718.