Effects of powder morphology on stereolithography additive manufactured Al2O3 ceramic

The digital light processing (DLP) for the preparation of alumina ceramics (Al2O3) is characterized by high molding accuracy and fast rates, making it show great promise for applications in high-end ceramic manufacturing. However, its forming process is greatly influenced by the photosensitive slurry. Although a large number of studies have been conducted to investigate the influence of different variables of the slurry on photo curing, the mechanism of the influence of the powder morphology of the Al2O3 raw material is still unclear. In this study, two kinds of slurry were prepared from spherical and laminated Al2O3 powders and DLP was carried out. The results showed that some of the spherical Al2O3 powder would break down after ball milling, resulting in a reduced flow-ability of the slurry. The relative density of the ceramic was 91.1 % and strength was 92.1 MPa. In contrast, the laminated Al2O3 could be oriented in the flow direction during flow, showing a lower viscosity. At the same time, the orientation allowed the lamellar powder to build up more tightly. The relative density of the ceramic was 93.2 % and strength was 165.5 MPa.