Strategizing with Unique Hot Isostatic Pressing Treatments to Increase Productivity During Post-Processing and Take Advantage of Microstructural Heterogeneities in Laser-Melted Inconel 718 Parts

Hot isostatic pressing (HIP) treatments are typically applied to additively manufactured parts to seal internal porosity and improve reliability of the component. Ni-based super alloys require multiple heat treatments to produce a microstructure that can withstand high-temperature environments. In this work, Inconel 718 parts were manufactured by laser powder-bed fusion, subjected to a range of HIP and heat treatments, and machined into a geometry that allows for high-throughput tension testing thereby removing the following variables: surface roughness and contour microstructures. This goal of this study is to simplify heat treatment routes while maintaining satisfactory tensile performance. The tailored heat treatment avenues will attempt to accomplish the following: avoiding a stress-relief, minimizing the number of aging steps, minimizing grain growth, sealing porosity with a minimum HIP pressure, and avoiding recrystallization to retain dislocation cell networks. SNL is managed and operated by NTESS under DOE NNSA contract DE-NA0003525.