Manufacturing cellular materials via three-dimensional printing of spray- dried metal oxide ceramic powder

Cellular materials, metallic bodies with gaseous voids, are a promising class of materials that offer high strength accompanied by a relatively low mass. Unfortunately, existing manufacturing techniques constrain a designer to a predetermined part mesostructure, material type, and macrostructure. In this paper, the authors document their design rationale for the selection of the Three-Dimensional Printing (3DP) additive manufacturing process as a means to fabricate metallic cellular materials. This is achieved by selectively printing a solvent into a bed of spray-dried metal oxide ceramic powder. The resulting green part undergoes reduction and sintering post-production processes in order to chemically convert it to metal. the authors document progress towards creating a manufacturing process that can create threedimensional, low-density cellular metal parts with designed mesostructure. Specifically, the authors have augmented the three-dimensional printing process (3DP) for the creation of green parts (formed from metal oxide powders) that are suitable for conversion to metal via thermal chemical postprocessing. The reduction and sintering post-process, a feature of the manufacturing process for the realization of linear cellular honeycombs, is described in Section 2. In Section 3 the authors present their rationale for the selection and augmentation of the 3DP process through a functional analysis of additive manufacturing processes. Preliminary results are provided in Section 4 along with closing comments in Section 5. 2 REDUCTION OF METAL OXIDES TO CREATE METAL CELLULAR MATERIALS In an effort to address the limitations found in the creation of cellular materials via direct-metal AM technologies, the authors look to other processes as a means of creating metallic parts. Specifically they look to the Georgia Tech Lightweight Structures group’s work in creating metallic linear cellular alloys (LCA) from metal oxide precursors. Finished Metal Part Oxide Powders H2O Compounding Additives Step One Paste Preparation