Infrared irradiation to drive phosphate condensation as a route to direct additive manufacturing of oxide ceramics

This paper introduces a fast, low-temperature, pressureless process to chemically bind ceramic parts with the help of infrared (IR) irradiation and phosphate binder condensation. Ceramic components are synthesized from slurries of ceramic powders and Al(H2PO4)3 binder that are irradiated with short-waved IR light capable of heating the system to 350 & DEG;C. This irradiation is found to be sufficient to drive phosphate condensation, binding the ceramic powders together within a matter of seconds. The IR-irradiated components show an increase in density and Vickers hardness. Layer-by-layer spraying and irradiation is demonstrated as a route to additive manufacturing using various ceramic chemistries. While further optimization is needed to control desired microstructure, this process of using chemically bonded ceramic binders with IR heating for additive manufacturing shows the potential to find applications in various ceramic systems, including refractories, bone implants, electronics, and thermal barrier coatings.