Our work employs thermal histories extracted from a temperature-dependent heat conduction model to simulate the solidification microstructure of the nickel-based superalloy CM247LC. The results reveal a transition in solidification morphology from highly cellular structures at low energy densities to predominantly dendritic structures at high energy densities. These dendritic solidification morphologies are concluded to promote the formation of microcracks observed in CM247LC at elevated energy densities through trapping of nanovoids in the interdendritic liquid region.

Furthermore, the inherent processing difficulty of CM247LC is shown to arise from competing defect formation mechanisms: low energy densities lead to lack-of-fusion porosity, while high energy densities promote microcrack formation. These findings are corroborated by coupling the phase-field solidification results to a decoupled, dislocation-density-based crystal plasticity framework that assumes jog-limited dislocation motion during solidification. Experimental validation is provided through comparisons between simulated microstructures and those observed via scanning electron microscopy and optical microscopy.