Unravelling the origin of multiple cracking in an additively manufactured Haynes 230

In this work, by using multi-scale characterizations from electron channeling contrast imaging (ECCI) to atom probe tomography (APT), we directly evidenced that the massive cracking events in selective-laser-melted (SLMed) Haynes 230 superalloy are due continuous decoration of an M23C6-type thin film at grain boundaries. The high-melting-point nature carbide rules out possibility liquidation cracking, while long and straight surface facilitates stress-induced solid-state cracking. Impurities, Si, Mn Fe, greatly enhance susceptibility despite interesting fact they strongly depleted carbide.