Influence of Post Heat Treatment on the Mechanical and Metallurgical Properties of WAAM-Deposited Inconel 718 Wall

Abstract The current study focuses on the fabrication of Inconel 718 alloy wall using the Wire Arc Additive Manufacturing process with Cold Metal Transfer (WAAM-CMT). A detailed assessment of both mechanical and metallurgical characteristics was carried out on specimens produced in the as-deposited condition as well as after post-deposition heat treatment. The mechanical response was evaluated through tensile testing, impact toughness studies, and microhardness measurements, providing insights into strength hardness and toughness variations. Microstructural characterization were carried using optical microscope and phase identification was performed by X-ray Diffraction (XRD). In addition, fractographic observations of fractured samples from tensile and impact tests were conducted using SEM to identify failure mechanisms. The findings reveal that annealing at 1100 °C for two hours followed by furnace cooling enhances strength and hardness, while slightly reducing impact toughness, demonstrating a trade-off that defines an optimal balance for specific engineering requirements. Hence, WAAM-CMT fabricated and heat-treated Inconel 718 demonstrates promising potential for engineering applications demanding high performance and durability.