Evaluation of energy density measures and validation for powder bed fusion of polyamide

For powder bed fusion additive manufacturing, energy density captures the interrelated effects of beam power/size, scanning speed, hatch spacing and layer thickness. Relations for energy density include linear, areal and volumetric forms, developed empirically or theoretically. Various energy density formulations for laser sintering of polyamide 12 were evaluated based on correlation to measured part mass relative densities. Test pieces were printed with varying parameters: laser power, hatch spacing and layer thickness. Results show that total energy density is correlated to both and mass density and strength for a volumetric energy density.