Controllable interlayer shear strength and crystallinity of PEEK components by laser-assisted material extrusion

Laser-assisted material extrusion was used in this study to realize high-performance 3D printing of semicrystalline polymers. A CO2 laser device was simply integrated into a traditional fused deposition modeling printer to supply the laser. The sample's surface temperature was changed by controlling the laser power during printing, and thus the interlayer shear strength and crystallinity could both be effectively controlled. By implementing the laser-assisted process, the optimal interlayer shear strength of poly(ether ether ketone) (PEEK) could be improved by more than 45%, and the degree of crystallinity of PEEK was simultaneously improved by up to 34.5%, which has approached to the typical crystallinity of 35%. Therefore, the process provides a very effective solution for additive manufacturing of semicrystalline materials and helps clearly to establish a controllable mapping relationship between the laser parameters and material properties.