Metal Additive Manufacturing using complex beam shaping

Large thermal gradients, complex melt pool instabilities and poor absorptivity are application-limiting detriments in laser powder bed fusion-enabled metal additive manufacturing (AM), ultimately resulting in poor mechanical properties. Current approaches to improving the mechanical robustness of structures printed using metal additive manufacturing (AM) come at the expense of print reliability, consistency cost and integrability. Here, we employ laser beams shaped in amplitude, phase and polarization, to deliver controlled optothermal profiles on the powder bed. Unique optical properties of such beams (such as non-diffractive propagation) result in an improved combination of reduced porosity, increased part density, lower surface roughness and robust tensile properties across a broad scan parameter range, compared to conventional beams. We employ Multiphysics simulations and highspeed imaging for feedback and validation for printing SS 316L.