Enhancing dynamic property in additive manufactured IN738LC alloy through cell orientation control

Cell structures are common substructures in additive-manufactured (AM) superalloys, yet their influence on high strain-rate dynamic behavior remains unclear. Herein, two IN738LC alloys with different cell orientations were fabricated via AM and assessed for dynamic behavior at strain rates of ∼10⁵/s using flyer-plate impact tests. Results show that preferential cell growth along the building direction (BD) enhances spall strength by 12–13% (4.36∼4.51 GPa) compared to random orientations (3.91∼3.99 GPa). The enhancement arises from cell alignment along the BD. This alignment makes the cell wall, a damage nucleation site, parallel to the impact direction, restricting damage void coalescence and crack propagation.