An Effective Strengthening Strategy of Nano Carbide Precipitation and Cellular Microstructure Refinement in a Superalloy Fabricated by Selective Laser Melting Process

An effective strategy to strengthen a superalloy processed by selective laser melting (SLM) is proposed. The aim increase the yield strength of Inconel 718 fabricated SLM beyond 1400 MPa, which has never been achieved before. In this study, various NbC additions (0.0%, 0.5%, 1.0%, and 5.0% weight) were added in powder bed 718, two types post-SLM heat treatments investigated, i.e., solution treated plus aging (STA) direct (DA). With addition, smaller depth melt pool finer dendritic cells obtained. Both STA DA promoted precipitations γ′ γ″. eliminated cellular dendrites induced grain growth while retained as-built dendrites, size, nano-carbide from rendering significant 326.2 MPa strength. work, 0.5% addition exhibited record-high 1461 ultimate tensile 1575 for manufacturing process according literature data to-date.