Dispersion and properties of zirconia suspensions for stereolithography

Abstract

Stereolithography is an attractive technique for the fabrication of complex‐shaped ceramic components with high dimensional accuracy. One of the challenges in this technology is the development of high solid loading, low viscosity photosensitive ceramic suspension. In this study, the dispersion of zirconia in photocurable resin and the slurry properties were intensively investigated. Rheological measurements showed that DISPERBYK‐103 proved to be an effective dispersant. 42 vol% ZrO2 suspension was successfully prepared using 3.5 wt% DISPERBYK‐103 as the dispersant, with a suitable viscosity (4.88 Pa·s) below the maximum allowable viscosity value (5 Pa·s) for stereolithography applications. The adsorption behavior of DISPERBYK‐103 on the surface of zirconia powders was characterized by TG and FT‐IR, confirming the dispersion effect of dispersant. Contact angle measurements were also conducted to show that the adsorption of DISPERBYK‐103 could help to improve the wettability between powder and photocurable resin. Results showed that DISPERBYK‐103 was effective for the preparation of suitable slurries for the development of ZrO2 ceramics through stereolithography.

Fabrication of zirconia all‐ceramic crown via DLP‐based stereolithography

“…It may be due to the heat‐treatment process, during which the ceramic particles stacked freely firstly and followed by a possible particle rearrangement near the interface. In consequence, the boundaries became blurred . The spherical zirconia particles were homogeneously distributed in photopolymerized binder without noticeable serious agglomeration as shown in Figure B, indicating that the powder possesses perfect dispersity in resin.…”

“…This resin is an acrylate‐based product and shows no sensitivity to moisture. It mainly contains epoxy acrylate (EA), 4‐acryloylmorpholine (ACMO), trimethylolpropane triacrylate (TMPTA) and a radical photoinitiator (Diphenyl(2,4,6‐trimethylbenzoyl)phosphine oxide, 0.03 g for each gram of total monomers) . Variquat CC‐42 NS (a polypropoxy quaternary ammonium chloride), Hypermer KD‐1 (a cationic polymeric dispersant), Solsperse 24000 (a 100% active polymeric dispersant), Triton X‐100 (Octylphenol Ethoxylate) and SP‐710 (a block copolymer with acidic groups) were selected as the dispersants to stabilize the zirconia particles in the resin.…”

3Y-TZP DLP Additive Manufacturing: Solvent-free Slurry Development and Characterization

“…Figure 7a is the FTIR spectrum of Disperbyk-111. The peaks at 1,099 and 1,730 cm -1 , present in the FTIR spectrum of this dispersant, correspond to the stretching vibration peaks of COC and C=O 33 . Figure 7b shows that the spectrum of the zirconia powder modified with Disperbyk-111, after being rinsed and dried, presents similar stretching vibration (at 1,105 and 1,731 cm -1 ), which is not present in the as-received zirconia powder.…”

“…Figure 1 shows the viscosity of zirconia photosensitive slurries used in additive manufacturing by VP 1, [32][33][34][35][36]38 according to volume fraction (at a shear rate of 30 s -1 ) and the dotted rectangle identifies the preferred characteristics for suspensions (at least 40 vol% solid loading and up to 3 Pa.s viscosity). It is important to note that the three studies that achieved these characteristics used solvent-based slurries.…”

Effects of the internal structures of monolith ceramic substrates on thermal and hydraulic properties: additive manufacturing, numerical modelling and experimental testing

“…However, reducing the layer thickness to increase the bonding of the layers as a consequence increases the building time. Correspondingly, the viscosity of the suspension must be optimised to ensure uniform layer recoating during the build [40]. Nevertheless, AM can overcome the traditional ceramic manufacturing methods limitations, such as complex geometry production.…”