Fabrication of highly transparent yttria by DLP-based additive manufacturing

Abstract

High-quality transparent yttria (Y2O3) is produced using various shaping techniques; however, the geometric control limits of shaping processes hinder its utilization and application. Thus, this study proposed digital light processing (DLP)-based additive manufacturing (AM). Although popular, transparent ceramic AM faces issues owing to limited transparency and simple shapes. This study fabricated a three-dimensional-structured transparent Y2O3 ceramic using DLP-based AM assisted by vacuum sintering and revealed the critical factors governing its transparency. Zirconia and lanthana were utilized as sintering additives to regulate grain growth. Slurry conditions (dispersant concentration and solid loading) were optimized to control the homogeneity and density of the green body. After pre-sintering and vacuum sintering, the transparent Y2O3 ceramics exhibited a transmittance of 94.86 % of the theoretical limit and a relative density of 99.89 % owing to a fine-grained dense microstructure. The fabricated lens array structures of Y2O3 demonstrated a notable level of transparency and satisfactory optical imaging capabilities.