Study of alumina ceramic parts fabricated via DLP stereolithography using powders with different sizes and morphologies

Abstract

Selecting suitable ceramic powders for the preparation of UV‐curable ceramic suspensions, which are well suited for printing processes and production of high‐performance ceramic components, is a crucial factor in the practical industrial application of digital light processing (DLP) stereolithography. Therefore, this study aims to provide a comprehensive evaluation of alumina ceramic parts fabricated via DLP stereolithography using a variety of alumina powders with varying sizes and morphologies. Experiments were conducted to examine the rheological response, recoating performance, and curing behavior of UV‐curable alumina suspensions. Additionally, the thermal decomposition behavior of three‐dimensional (3D)‐printed green‐bodies, as well as the physical and mechanical properties of 3D‐printed sintered alumina components were thoroughly investigated. The best physical and mechanical performances were achieved by printing 55 vol% suspensions prepared using near‐spherical AA04 alumina powders (median diameter .4 μm). This study elucidates the effects of ceramic particle size and morphology on the entire technological process of DLP‐based ceramic stereolithography, thereby establishing the guidelines for the fabrication of high‐performance 3D‐printed ceramic objects in industrial and engineering production by selecting appropriate ceramic powders.

Fabrication of ZTA crowns with simultaneously improved isotropy on mechanical property and surface quality by DLP

“…24 As for rheological behavior, the photocurable Al 2 O 3 /YSZ suspensions with excellent stability, high solid loading, low viscosity, and pronounced shear-thinning and self-leveling behavior are usually desired to prevent sedimentation, enhance printability, and improve mechanical properties of sintered ceramic parts. 13 The retained sedimentation height versus the standing time for 15 wt% Al 2 O 3 /YSZ suspensions are shown in Figure 2A. In previous 10 days, with an increase in YSZ contents, ceramic suspensions exhibited more obvious sedimentation and worse stability, explained in terms of higher particle size and stronger agglomeration generation.…”

“…For the suspensions with different YSZ contents added, the viscosity at a shear rate of 30 s −1 was always bellow 3 Pa s, which could achieve a highly efficient layer recoating. 13,26 The viscoelastic property, thixotropic behavior, and self-leveling ability of 82 wt% Al 2 O 3 /YSZ suspensions were further systematically evaluated, as exhibited in Figure 2D-G. All suspensions exhibited remarkable viscoelastic behavior.…”

“…Digital light processing (DLP)based additive manufacturing (AM) allows for efficient forming of complex-shaped ceramic components with excellent mechanical performance and high dimensional accuracy. [7][8][9][10][11][12][13][14] Therefore, the use of DLP technology for fabricating ZTA composite ceramic objects has emerged as a promising approach for dental restoration and repairation applications in recent decades, and it can be used to fabricate ZTA all-porcelain crowns that meet dental standards (ISO 6873:2015). [15][16][17] However, the layer-bylayer forming characteristics of DLP can cause anisotropy on ZTA all-porcelain crowns, which has become a bottleneck hindering their clinical applications.…”

Comprehensive Review on Fabricating Bioactive Ceramic Bone Scaffold Using Vat Photopolymerization

“…Some studies suggest that the curing depth should be at least three times the printing thickness. 188 Recently, Mohammadi et al 185 investigated the effect of the ratio of curing depth to layer thickness (CD/LT) on the strength of HA scaffolds. High CD/LT resulted in overcured layers and frequent vertical cracking.…”

“…It is recommended to select the exposure time and layer thickness based on the photosensitive parameters of the ceramic slurry. , A layer thickness smaller than the curing depth can ensure reliable connection between layers of the green body and suppress delamination after sintering. Some studies suggest that the curing depth should be at least three times the printing thickness . Recently, Mohammadi et al investigated the effect of the ratio of curing depth to layer thickness (CD/LT) on the strength of HA scaffolds.…”