Design of Experiments based optimization of Direct Energy Deposition Inconel 625 processing for a power generation turbine blade

Abstract

Laser Metal Deposition (LMD) ability to precisely fabricate complex geometries layer by layer, along with its capability to repair and enhance existing components, has ushered in new frontiers of design freedom and innovation. As industries continually seek solutions for increased efficiency and performance, LMD offers an avenue to unlock novel possibilities, enabling the production of high-quality, intricately designed parts while simultaneously reducing material waste, with significant build rate when compared to other metal AM processes. The unique properties of nickel-based superalloys, including exceptional high-temperature strength and corrosion resistance, make them indispensable materials for critical applications, particularly in aerospace, power generation, and the energy sector. This research paper presents a comprehensive investigation into the process optimization of laser melting deposition for Inconel 625, a high-performance nickel-chromium-based superalloy. The study employed a center cubic design as a Design of Experiments (DoE) framework, with a primary focus on achieving the maximum tensile strength as the optimization objective. A series of quasi-static tensile tests was conducted to evaluate the mechanical properties of the deposited material, while optical microscopy was utilized to analyze the cross-sectional characteristics, including deposition density and defect sizes.