Structural Integrity Assessments for Validating Directed Energy Deposition Repairs of Integrally Bladed Rotor

Abstract

Abstract Considerable steps to assess the structural capability of laser directed energy deposition (DED) aim to determine the viability of repair processes for integrally bladed rotors (IBRs). Two laser DED processes are under investigation in this study: wire fed and blown powder feedstock. Using a small subsonic Titanium 6Al-4V fan as the component of interest, a series of tests and associated models for laboratory specimens, subcomponents, and components are necessary for proper assessment of material structural properties pertaining to the intended mission of the IBR. Experimentation on laboratory specimens acquire properties such as tensile strength, elongation, low cycle fatigue (LCF), high cycle fatigue (HCF), crack growth rate, and fracture toughness. Subcomponent test articles fabrication occurs by sectioning an operational IBR into individual blades for vibration HCF assessment. Component level testing focuses on LCF and overspeed strength acquired from spin rig testing. Even though the full IBR repair validation of laboratory specimen, subcomponent, and component testing has yet to be completed, the results to-date for laser DED repairs are promising. Furthermore, this plan for structural integrity assessment can serve as a reference for validation of future IBR repair processes.