Interphase effects of polymer laminae 3D-printed via multi-material jetting

Multi-material 3D printing poses challenges affecting printed component quality and mechanical properties. A key issue stems from resolution limitations, hindering seamless transitions between materials. Consequently, a material mixing zone (interphase) forms at dissimilar material boundaries, causing mechanical inconsistencies, significantly impacting overall mechanical performance of 3D printed products. For multi-material polymer jetting, printing direction and layer thickness significantly influence mechanical properties of 3D printed products. This study aims to assess these effects using a two-phase lamina as a representative material system. Printing direction, layer thickness, and material mixing's impact on laminae's in-plane mechanical properties will be investigated via macro- and micro-scale mechanical experiments and finite element simulations. Specimens will be fabricated using a Stratasys Objet260 Connex3 multi-material 3D printer. Mechanical experiments, including macro-scale uni-axial tension tests, nano-indentation, and scanning electron microscope (SEM) characterization, will be conducted to characterize properties. An anisotropic material model is introduced to the FE model of the material system to predict the effects of printing direction and material mixing in the interphases of 3D printed laminae.