Highly textured 3D-printed translucent alumina through pressure-assisted sintering

Templated grain growth is a promising method for the fabrication of translucent alumina ceramics and a possible way to circumvent light scattering due to birefringence. In the present paper the effect of temperature, heating rate and dwell time on grain size, orientation, hardness and in-line transmittance is investigated on 3D-printed textured alumina. The samples were prepared by lithography-based ceramic manufacturing (LCM) of suspensions with fine-grained alumina, seeded by high aspect ratio templates and sintered by spark plasma sintering (SPS). A fully developed textured microstructure was achieved at 1600 °C for 1 h, whereas sufficient in-line transmittance of 54.6 % at 550 nm was achieved at 1700 °C for 3 h, albeit at the cost of considerable grain growth and loss of microstructural texturing.