| Abstract Scope |
Laser powder bed fusion (LPBF) additive manufacturing offers unprecedented design freedom including the fabrication of technologically relevant lightweight, topologically optimized lattice structures. A limitation in the LPBF process however, is the lack of control over residual stress, negatively affecting mechanical properties and geometrical accuracy. In this regard, using thermomechanical modeling as the primary investigative tool and Inconel 718 as the material of choice, the effect of part geometry, strut diameter, and lattice type on developed residual stress and part distortion is examined. Particular attention is paid to heat accumulation and thermal gradients within the fabricated part and their interplay with residual stress. Using these models as the basis, recommendations are provided for LPBF processing parameters to limit residual stress within topologically optimized lattice structures, which are experimentally verified via targeted fabrication of such structures. |