Brief Paper: Geometric Determinants of Material Jetting-Enabled Bi-Material Interface Integrity Using Polyjet 3D Printing

• DOI: 10.1115/msec2024-122414
• Publication Date: 2024-08-20T17:55:53Z
• Authors: Nolan J. Aberdeen; Kimia Forghani; Ryan D. Sochol

Abstract Among the wide range of additive manufacturing — or “three-dimensional (3D) printing” — technologies, “material jetting” approaches are distinctively suited for multi-material fabrication. Because material jetting strategies, such as “PolyJet 3D printing”, harness inkjets that allow for multiple photopolymer droplets (and sacrificial support materials) to be dispensed in parallel to build 3D objects, distinct materials with unique properties can be readily unified in a single print akin to combining multiple-colored inks using a conventional 2D color printer. Although researchers have leveraged this multi-material capability to achieve, for example, 3D functionally graded and bi-material composite systems, there are cases in which the interface between distinct materials can become a key region of mechanical failure if not designed properly. To elucidate potential design factors that contribute to such failure modes, here we investigate the relationship between the interface design and tensile mechanical failure dynamics for PolyJet-printed bi-material coupons. Experimental results for a select set of bi-material sample designs that were 3D printed using a Stratasys Objet500 Connex3 PolyJet 3D printer and subjected to uniaxial tensile testing using a Tinius Olsen H25K-T benchtop universal testing machine under uniaxial strain revealed that increasing the surface contact area between two distinct materials via changes in geometric design does not necessarily increase the interface strength based on the length scales and loading conditions investigated in the current study and that further studies of the role of multi-material geometric designs in interface integrity are warranted to understand potential mechanisms underlying these results. Given the increasing interest in material jetting — and PolyJet 3D printing in particular — as a pathway to multi-material manufacturing in fields including robotics and fluidic circuitry, this study suggests that multi-material interface geometry should be considered appropriately for future applications.