Vat photopolymerization 3D printing of ceramics: Effects of fine powder

The objective of this work is to test a novel approach to increase the bulk density of ceramic parts made by vat photopolymerization. It is hypothesized that the bulk density of the resultant ceramic parts increases by introducing a small amount of fine powder to the suspension feedstock. A commercial 3D printer was used to produce samples from different suspensions. The printed samples then underwent debinding and sintering processes, after which density and porosity measurements and microstructural characterization were carried out. It could be summarily concluded that the substitution of a small volume of a coarser (0.8 mu m) powder with a finer powder (0.3 mu m or 0.5 mu m) in the suspension markedly increased the bulk density and decreased apparent porosity of the printed and sintered parts without worsening the printability of the suspension. Scanning electron microscopy showed the fine powder improved the necking during sintering, contributing to the increased density and decreased porosity. (C) 2019 Society of Manufacturing Engineers (SME). Published by Elsevier Ltd. All rights reserved.