|About this Abstract
||2023 TMS Annual Meeting & Exhibition
||Quantifying Microstructure Heterogeneity for Qualification of Additively Manufactured Materials
||Strong impact of minor elements on the microstructural evolution of an additively manufactured Inconel 625 alloy
||Mo-Rigen He, Arunima Banerjee, Christopher Marvel, Samuel Price, Ian McCue, William Musinski, Kevin Hemker
|On-Site Speaker (Planned)
Additively manufactured metallic materials often see inhomogeneous distribution of alloying elements, which can make a strong impact on the as-built microstructure and its evolution during post-build heat treatments. In this study, an Inconel 625 alloy made with laser powder-bed fusion is characterized with comprehensive electron microscopy techniques. The as-built samples show enrichment of both major (Nb,Mo) and minor (Si,N) solutes at the columnar sub-grain cell walls, whereas stress-relief heat treatments promote formation of globular (Nb,Mo,Si,N)-rich M6X and (Nb,N)-rich MX precipitates. Absence of the detrimental needle-shaped delta-Ni3(Nb,Mo) phase is attributed to the higher Si and N contents at the cell walls and their modification of the thermodynamics of precipitate formation. The effect of sample geometry, grain texture, and precipitates on the mechanical response of the alloy is assessed with printed thin-wall elements. As demonstrated herein, rational control of minor elements requires further attention in additive manufacturing.