Modelling of Additive Manufacturability of Nickel-Based Superalloys for Laser Powder Bed Fusion

The additive manufacturability of nickel-based superalloys for laser powder bed fusion (LPBF) technologies is studied by considering the in-process cracking mechanisms. The additive manufacturability of nickel-based superalloys largely depends on the resistance to the liquid and solid-state cracking. Herein, we propose a two-parameter-based, heat resistance and deformation resistance (HR-DR) model, accounting for the relation between chemical composition (both major and minor elements) and cracking susceptibility, which is generalized from the elemental microsegregation behavior and mechanisms of LPBF process induced cracking. The proposed model is validated by the LPBF experiments in this study and by the hitherto reported data in LPBF superalloys community. The HR-DR-model is found to be a theoretically acceptable and easy-to-use approach for the prediction of in-process cracking of nickel-based superalloys during LPBF. The influence of alloying elements and the γ′ precipitates on the additive manufacturability is discussed. The model provides a path for designing not only new solid solutioning, but also and more importantly γ′ strengthened nickel-based superalloys for LPBF applications.