An Analysis of Variation Correlating Post Processing Infiltrate Types, Build Parameters and Mechanical Characteristics for Binder Jet Built Parts

Abstract

The 3D Printing (3DP) “binder jetting” process is an additive manufacturing process that fabricates components and assemblies by layering powered material, and applying a binder where a ‘solid interior’ should be. This process creates brittle components as a powder is set with a weak binder material; however, the component strength characteristics can be significantly modified when infiltrating the component during post processing operations. The different factors that can influence the mechanical properties when engaging in post-processing operations need to be understood. A full factorial design of experiments (DOE) is conducted for tensile, compressive, and flexural specimens for 10 infiltrate and various build conditions. The experiment and resultants are set up to perform an analysis of variance (ANOVA). All of the observed stress-strain curves for the specimens are non-linear, or have limited linear regions. The infiltrate absorption depth affects the mechanical characteristics, and the binder jetting specimens are stronger in compression than tension. The tensile test results are similar to those of biological materials. Certain infiltrates do not improve the mechanical performance characteristics, which are validated using the Tukey method. This research needs to be extended in scope to include additional build orientations as well as torsion, fatigue, and notch tests to be able to predict model sensitivities effectively for components built using the binder jetting process, and to develop optimization strategies, which include time, material, and strength conditions.