Evaluating effect of manufacturing process on design in metal binder jetting

Metal binder jetting (BJT-MSt/M, MBJ) is a cost-effective metal additive manufacturing (AM) process due to its high deposition speed and support-free printing, enabling multiple parts to be nested in the build chamber. Despite its robust and accurate printing, challenges during depowdering and sintering can lead to part breakage or deformation. A thorough understanding of the manufacturing process chain and the associated challenges is required to consider these effects during part design. Currently, there is a lack of comprehensive studies on the design-related aspects of MBJ that address the critical depowdering and sintering aspects. This study investigates four key design aspects of MBJ related to depowdering, shrinkage-induced deviation, sag-induced deformation, and drag-induced deformation. Design guidelines were derived based on simple design features and compared with those of machine manufacturers, with successful manufacturing of feature sizes down to 0.4 mm; the shrinkage-induced deviation was analyzed and quantified for non-cubic design artifacts with median relative deviations of +1.6 to –3.1%; and sintering-induced deformation based on sag and drag effects was analyzed using five distinct design artifacts. The deformations are demonstrated, the impact of key design parameters is quantified and their significance is proven based on suitable statistical methods. Therefore, by demonstrating the effects and the influence of specific design parameters, this study provides an overview of potential deviations that may occur during manufacturing. Designers can mitigate these effects through measures taken in the design phase. The results of this study contribute to an in-depth understanding of design for MBJ, thereby facilitating first-time-right manufacturing.