Influence of temperature field on the rheological properties and photopolymerization process of Mg2TiO4 microwave ceramic slurry during vat photopolymerization process

Temperature-field-assisted vat photopolymerization has been applied to prepare Mg 2 TiO 4 ceramics with few defects and remarkably reduced dielectric loss . These excellent properties could be attributed to the significantly reduced viscosity and increased curing depth of the prepared ceramic slurry with a high solid loading when the photopolymerization temperature reaches 65 °С. Increasing the temperature helped to increase the kinetic energy of the resin molecules and reduce the viscosity of the ceramic slurry. This ensured a smooth spreading of the slurry and suppressed the formation of intra-layer defects during the printing process. Additionally, increasing the curing temperature enhanced the activation energy of the free radicals and accelerated the transfer of molecular chains , thereby increasing the polymerization rate and curing depth of the slurry. This reduced the interlayer pores of the Mg 2 TiO 4 green bodies. Thus, Mg 2 TiO 4 ceramic slurry with a high solid loading could be successfully printed by applying a temperature field. Significantly fewer defects were found in Mg 2 TiO 4 ceramics printed with 57.5 vol% solid loading than those in the samples printed with 50 vol% solid loading. The quality factor of Mg 2 TiO 4 ceramics sintered at 1550 °С for 4 h using ceramic slurries with 57.5 vol% solid loading could reach 150,000 GHz when printed at a curing temperature of 65 °С, this value is equivalent to that of dry-pressed ceramics.