Erich D. Bain,
, , Thomas C. Parker,
Laser sintering (LS) of polyamide 12 (PA12) is increasingly being adopted for industrial production of end-use parts, yet the complexity of this process coupled with the lack of organized, rigorous, publicly available process-structure-physical property datasets exposes manufacturers and customers to risks of unacceptably poor part quality and high costs. Although an extensive scientific literature has been developed to address some of these concerns, results are distributed among numerous reports based on different machines, materials, process parameters, and users. In this study a wide range of physical techniques are used to characterize a commercially important LS PA12 feedstock processed along four build dimensions of a modern production LS machine and compared to the same material formed by conventional melt processing. Results are discussed in the context of the literature, offering novel insights including the magnitude of environmental humidity effect on glass transition temperature, localization of semicrystalline phase changes due to LS processing, effect of chemical aging on melt viscosity over time, porosity orientation relative to LS build axes, and microstructural effects on tensile properties and failure mechanisms identified through fractography.
Integrating Materials and Manufacturing Innovation
Powder bed fusion, PBF, polymer, selective laser sintering, SLS, rheology, thermal characterization, tensile, ATR, nylon 12, additive manufacturing