Inconel 718, processed by Laser Powder Bed Fusion of Metals (PBF-LB/M), exhibits epitaxial dendrite growth, resulting in a columnar texture with anisotropic properties. While columnar microstructures offer creep resistance, equiaxed microstructures provide more balanced mechanical properties. Selective formation of columnar or equiaxed grains with tailored textures and grain sizes can enhance mechanical properties in specific areas of complex parts. Nevertheless, it is still a persistent challenge to understand tailoring as-built microstructure in PBF-LB/M process.


Recent advancements in beam shaping, coupled with new scanning strategies such as beam splitting, offer practical solutions for customizing heat flow direction in the PBF process, the as-built microstructure. This research aims to systematically study how the scanning strategy and beam shapes affect the texture, grain size, and morphology of as-built microstructure in volumetric parts. Various laser beam shapes, including symmetrical and novel asymmetrical ones like c-shape, rectangular, and line intensity distribution, are employed to manufacture IN718 parts. The study prioritizes high productivity, exceeding 20 mm³/s building rate across chosen process parameters compared to state-of-the-art methods. The findings suggest that the beam shape plays a significant role in enhancing productivity by expanding the process window, increasing beam diameter, and enabling larger hatch distances. While implementing novel scanning strategies, such as beam splitting, customize as-built microstructures, particularly in terms of anisotropy, texture, grain sizes and morphology.