DLP 3D-printing of dual porous YSZ ceramics with high mechanical properties using PMMA microsphere as pore-forming agent

Dual porous yttria-stabilized zirconia (YSZ) ceramics were fabricated via digital light processing (DLP) additive manufacturing using polymethyl methacrylate (PMMA) microspheres as pore-forming agent for the first time. The results showed that the introduction of PMMA microspheres effectively reduced the viscosity of the photosensitive YSZ ceramic slurry used in DLP printing, improved the cured depth of the slurry, and did not exert a strong influence on stability. After sintering at 1400°C, pores with dual scales were generated in the ceramics, while exhibiting the optimal physical and mechanical properties. With the increase of PMMA content from 0 to 40 vol%, the open porosity increased from 1.96% to 34.06% and the density decreased from 5.92 to 3.82 g/cm³, respectively. The compressive strength and thermal conductivity of porous ceramics decreased from 350.54 to 99.85 MPa and from 2.80 to 1.46 W/(m⋅K), respectively. This investigation opens up new prospects for the fabrication of porous YSZ ceramics with low thermal conductivity and high mechanical properties.