Process Optimization for Hydrothermal-Assisted Jet Fusion Additive Manufacturing of Ceramics

Hydrothermal-assisted jet fusion (HJF) process is a new additive manufacturing (AM) method for ceramics, which is capable of fabricating ceramic 3D structures without the need for organic binders. The HJF process selectively deposits a water-based solution into a ceramic powder bed in a layer-by-layer manner and fuses particles together through a hydrothermal mechanism. Since no organic binder is used in the HJF process, such a binder-free AM method can produce ceramic parts with less energy consumed for binder removal and has the potential to reach the material’s theoretical properties such as full density and exceptional mechanical strength. Nevertheless, the fabricated parts by the HJF process still suffers from issues, such as over fusion base-layer damage, pattern shifting, etc. In this paper, the effects of process parameters (e.g., stroke, droplet size, press number, final press, etc.) on the fabrication quality (e.g., diffusion behavior of deposited inks and shape fidelity of the fabricated parts, etc.) of the HJF process are studied. Optimum process settings are identified to alleviate those quality issues, and 3D structures with high shape fidelity were successfully fabricated to highlight the capability of the HJF process in achieving ceramic 3D structures with high accuracy and high performance.