Laser powder bed fusion (PBF-LB) of superalloys produces a distinctive cellular solidification structure due to high thermal gradients and rapid solidification velocities. This study investigates cellular growth mechanisms in additively manufactured \(\hbox {GammaPrint-700}^{\hbox {TM}}\) , a CoNi-based superalloy, using advanced characterization methods including TriBeam tomography and direct electron detection EBSD at sub-micron resolution. Cells exhibit crystallographic growth along \({\langle {001} \rangle }\) directions rather than following the heat flux directly, comparable to dendritic growth. A geometric model successfully predicts cellular growth directions by minimizing angles between preferred \({\langle {001} \rangle }\) orientations and local thermal gradients. Within columnar grains spanning multiple build layers, cells accommodate alternating scan directions by switching between orthogonal \({\langle {001} \rangle }\) growth directions across the melt pool boundaries. Significant misorientation accumulation occurs within individual cells and between neighboring cells, ultimately resulting in bulk grain misorientation development. Impinging cells along grain boundaries create serrated interfaces in the as-printed state through solidification processes alone. These findings reveal that bulk grain rotations and residual stresses originate from cellular-scale deformation, with important implications for the mechanical properties of additively manufactured superalloy components.
