Rosenthal-based estimation of the extended solidification-condition envelope accessible by the 3DMD process

High-speed directed energy deposition (HS-DED) comprises a range of process variants capable of substantially higher travel speeds than conventional DED. This study focuses specifically on the exclusive 3DMD process and provides an unusually broad operating range of process parameters with reduced dilution, suggesting access to an extended range of solidification conditions. However, quantitative comparisons of the thermal-gradient–solidification-rate (G–R) space accessible by 3DMD and conventional metal additive-manufacturing (AM) processes remain limited. This work presents a comparative Rosenthal-based screening analysis for conventional AM processes and HS-DED using the operating range of a Ponticon pE3D system. All process families were evaluated for Inconel 718 using a consistent thermal model and post-processing procedure. The resulting maps indicate that 3DMD spans a substantially broader G–R envelope than conventional DED. Lower-speed conditions overlap with DED, while higher travel speeds extend toward solidification-rate and cooling-rate regimes associated with powder-bed fusion. Lower dilution may further preserve regions characterized by lower G/R, increasing the range of solidification conditions retained in the deposited material. Although the analysis is intended as a comparative estimate rather than an exact prediction of process limits or columnar-to-equiaxed transition boundaries, it highlights the potential of 3DMD for enhanced control of solidification and microstructure, particularly in manufacturing of large components.