Tim Dreier, Ahmad Mezrab, Abdullah Riaz, Philip Töllner, Armin Springer, Hermann Seitz
Material extrusion additive manufacturing (MEX) of ceramics and metals enables fabrication of complex geometries. However, residual stresses during 3D printing cause torsional distortions during post-processing, compromising dimensional accuracy. This study systematically analyses the occurrence and mechanisms of torsional distortion in additively manufactured ceramic and metallic components. Ceramic and metallic feedstocks were selected due to their pronounced differences in thermophysical properties and sintering behavior, including thermal conductivity, binder content, and shrinkage anisotropy, which can influence residual stress development during MEX. The influence of key process parameters such as layer height, printing speed, and printing direction of the print head on torsional distortion is quantified. Experimental results demonstrate that distortions occur in both material systems but can be effectively controlled through printing process optimization. While increasing the layer height leads to a reduction in distortion, changes in printing speed had no significant effect on the degree of deformation. Alternating the printing direction between layers almost completely eliminated deformations, proving to be the most effective strategy across both material systems. These findings provide valuable insights for improving dimensional accuracy in additive manufacturing of highly filled polymers, and offer practical strategies for enhanced dimensional accuracy of final sintered parts.