A Framework with Examples for Printing Thermosetting Polymers Using Laser Powder Bed Fusion Additive Manufacturing

Thermoset polymers possess traits arising from their covalently crosslinked network structure that are distinct from thermoplastic polymers. These traits can manifest as relative increases in the performance properties of chemical resistance, stiffness, and strength particularly at elevated temperature. Although these performance properties are desired from additively manufactured parts, there are few engineering grade thermosetting polymers commercially available for any additive manufacturing (AM) fabrication method. This work describes some of the challenges when processing and formulating thermosetting powder feedstocks for the laser powder bed fusion (L-PBF) mode of AM. The thermal curing properties of three different commercially available thermosetting polymers made via L-PBF are compared. Surface temperature profiles collected during printing are used to predict the extent of crosslinking through a rudimentary isoconversional model and are compared against post-print measurements of residual cure.