Michael Willeke

The shift to energy‐efficient near‐infrared (NIR) diode lasers in polymer powder bed fusion (PBF‐LB/P) challenges standard polymer powders due to insufficient NIR absorption and necessitates tailored feedstock modifications. This study explores the potential of surface modification (s‐mod) of polyamide 12 (PA12) with LaB ₆ nanoparticles (NP) as a scalable alternative to conventional volume modification (v‐mod) with carbon black (CB). Despite a tenfold lower overall NIR absorbance, s‐mod PA12 achieves comparable melting behavior with only a 1.5‐fold increase in laser energy. Combined differential scanning calorimetry (DSC) and X‐ray diffraction (XRD) analyses reveal that surface‐localized absorption enables partial retention of α ‐domains at intermediate energy densities, consistent with a heterogeneous, surface‐dominated melting mechanism. At higher energies, s‐mod and v‐mod converge to fully γ ‐phase materials with comparable crystallinity. Mechanical testing demonstrates that intermediate s‐mod parts exhibit higher crystallinity, whereas fully molten s‐mod parts outperform v‐mod counterparts in tensile strength while maintaining ductility. Our findings indicate that s‐mod PA12 not only matches the processability of industrial v‐mod powders but also introduces new degrees of freedom for tailoring mechanical properties via controlled melting. Decoupling energy absorption from volumetric filler loading expands the material design space for NIR‐based additive manufacturing and paving the way for next‐generation, high‐performance polymer components.

It is well known that scan strategies have an essential role in powder bed fusion (PBF). For the comparison of different scan strategies, however, it is usually necessary to evaluate manufactured samples or run simulations. Given the typically lengthy nature of these processes, this study focuses on finding a rapid preprocess evaluation method for scan strategies using geometrical approaches: line buffer‐based calculations and a point density field. Both approaches only depend on the geometry of the scan strategy. While these calculations should apply to most PBF processes, this study uses the evaluation methods to predict the differences that four unique scanning strategies have in PBF of polymers using an near‐infrared laser source. Polyamid 12 powder with Lanthanum hexaboride nanoparticles and a commercial black‐dyed Polyamid 12 powder are used for processing. The calculation of the line buffer‐based surface energies of these scanning strategies correctly predicted the sequence in which the scanning curve appeared to have received the laser energy. Moreover, the defects observed in the manufactured samples appear to be related to the variation in point density of the scanning strategies. These promising results are the first step towards new preprocess evaluation methods, leading to improved predictability of different scan strategies.