Fabrication and properties of alumina ceramics shaped by digital light processing as an additive manufacturing technology

Ceramic slurries with different contents of Al2O3 were formulated and alumina ceramic parts with promising surface morphology were fabricated by using digital light processing photopolymerization-based additive manufacturing technology. The factors influencing curing depth of the slurries were studied, while the effects of powder content on shrinkage of the green bodies and microstructure, density, and hardness of the sintered bodies were evaluated. Although the curing depth was decreased with increasing content of Al2O3, all the five groups of slurries could be well cured, as the exposure time was set to be 16 s. According to TG-DTG curves, the weight loss of the samples was completed at about 580 degrees C. Samples from the slurries with 70 and 75 wt.% Al2O3 had dense microstructure, without obvious cracks at both the macro- and micro-scales. Furthermore, with increasing content of Al2O3 in slurries, the bulk density and hardness of sintered bodies were increased. It is believed that our results could be used as a reference for the fabrication of alumina ceramics through additive manufacturing technology.