Continuous DLP-based ceramic 3D printing using a composite oxygen-rich film

Abstract

The existing stereolithography-based ceramic 3D printing techniques are noncontinuous in a layer-by-layer method, which usually causes drawbacks of anisotropic mechanical properties, stair-casing effect, and the low fabrication rate. In this paper, a continuous DLP-based ceramic 3D printing is proposed to achieve the layerless ceramic manufacturing. In order to achieve this goal, a composite oxygen-rich film was designed with a microporous PET film and a PDMS coating to ensure a proper dead zone thickness according to the oxygen-controlled inhibition effect and low surface energy for releasing quickly from ceramic slurry. And a ceramic slurry with low viscosity was also prepared to match it. Then, the effects of influencing factors including the composite oxygen-rich film, ceramic slurry, and the print speed on the printing quality and geometrical overgrowth have been investigated. It shows that the geometrical overgrowth has a good linear relationship with this variable, the larger dead zone thickness, the higher solid content, and the low print speed, the larger the geometrical overgrowth. And the print speed does not worsen the surface quality. This proposed method can achieve the maximum speed of 143 mm/h and a surface roughness of 0.127 for a 40 vol% ceramic slurry. To demonstrate the utility of this system, parts of hollow structure, thin wall structure, and impeller structure have been successfully printed and sintered to ceramics with a condensed and porous structure. As a result, the proposed continuous DLP-based ceramic 3D printing technique provides a promising solution for ceramic 3D printing.