Optimized Zirconia 3D Printing Using Digital Light Processing with Continuous Film Supply and Recyclable Slurry System

Abstract

Stereolithography (SL) can fabricate complex ceramic parts layer by layer using computer-aided design (CAD) models. The traditional SL system utilizes a vat filled with ceramic slurry with a high solid content, which for ceramics contributes to several limitations and operational difficulties, and further renders it nonrecyclable mainly due to the presence of printed residue and its high viscosity. In this study, we utilized a continuous film supply (CFS) system integrated with a tape-casting type digital light processing (DLP) printer to fabricate zirconia prototypes with a solid content of 45 volume percent (vol.%). Various printing and postprocessing parameters were studied for optimization, to achieve a relative density of 99.02% ± 0.08% with a microhardness of 12.59 ± 0.47 GPa. Slurry reusability was also demonstrated by printing with recycled slurry to produce consistent relative density values in the range of 98.86% ± 0.02% to 98.94% ± 0.03%. This method provides new opportunities for material recycling and the fabrication of dense complex ceramic products, reducing the consumption of the material.

Effect of reactive diluent concentration on rheological and curing behavior of zirconia ceramic slurry for DLP printing

“…Obviously, all types of slurry could basically meet the printing requirements, and only the slurry with a concentration of 10 wt.% has a viscosity higher than 5 Pa·s. Even so, the thickest slurry has a viscosity of less than 5.5 Pa·s and could still be used on some special 3D printers 26 . However, the potential of improving the solid loading of zirconia ceramic powder is insufficient for this kind of slurry 14 .…”

Fracture toughness and hardness of in‐office, 3D‐printed ceramic brackets

“…23,24 Crack initiation is a process that forms cracks and this phenomenon (as it is anticipated) has been reported for 3D printed zirconia as well. 25 Therefore, it was chosen as the primary judgement tool for wing fracture appraisal.…”

“…Fracture toughness on the other hand which is the critical value of crack initiation and propagation outlines better the material's resistance to fracture 23,24 . Crack initiation is a process that forms cracks and this phenomenon (as it is anticipated) has been reported for 3D printed zirconia as well 25 . Therefore, it was chosen as the primary judgement tool for wing fracture appraisal.…”

A review on the ceramic additive manufacturing technologies and availability of equipment and materials

“…Al 2 O 3 [301], MgAl 2 O 4 spinel [302], SiC [303], Nd-doped YAG [304], Yb-doped YAG [305] Antenna Al 2 O 3 +glass [306], Ba 1-x Sr x Zn 2 Si 2 O 7 [307], MgTiO 3 +CaTiO 3 [308] Nuclear fusion Li 2 TiO 3 [309], Li 2 SiO 3 [310] Table VIII waste. Thus, machines that work with a small amount of material (60 mL) [316] and studies about recycling raw materials [286,354] have emerged. Also, the ceramic vat photopolymerization system made by the main suppliers (3DCeram, Admatec, Lithoz) surpasses US$100,000.…”

“…Finally, ceramic additive manufacturing is expected to follow the general 3D printing concern with sustainability [371] and expand studies on its environmental implications (considering materials savings in the life cycle and energy consumption [372]). There are already related studies about the reusability/recycling of feedstock [354], the use of recycled glass as raw materials [373,374], and steel dust waste as an additive in ceramic 3D printing [375]. Also, care must be taken about the environmentally hazardous materials involved in 3D printing and post-processing [15].…”