| Abstract Scope |
Complex manufacturing processes and challenges in scalability have long been a barrier for broader adoption of ODS alloys, despite of their exceptional high temperature creep properties. Recent advances in LPBF approaches have enabled the effective additive manufacturing of ODS alloy, with an example being a new NASA alloy GRX-810. Since TEM analysis is limited by its complexity and small observation volume, we present an alternative SEM-based multimodal approach integrating ECCI, EDS, EBSD, RKD, TKD and high-resolution imaging. Our study allows us to rationalize the outstanding high-temperature performance of GRX-810 by unveiling distinct evolution of critical microstructural features: oxide and carbide size distributions and volume fractions, grain and sub-grain boundary structures, and dislocation structures. Three distinct conditions are analyzed: as-built, HIPed, and post-creep. In the post-creep state, thermally stable oxide dispersion and grain boundary carbides effectively pin dislocations and stabilize the subgrain structure, leading to superior resistance to high temperature deformation. |