Microstructure and properties of transparent alumina ceramics fabricated by vat photopolymerization in combination with vacuum sintering

Transparent polycrystalline alumina (PCA) ceramics exhibit excellent mechanical properties and transparency, demonstrating significant potential for dental application, particularly in orthodontics. Using MgO as a sintering additive and combining vat photopolymerization (VPP) additive manufacturing technology with vacuum sintering, transparent alumina ceramics were successfully fabricated. This study investigated the effects of magnesium oxide content and sintering temperature on properties such as microstructure, mechanical properties, and optical properties. For alumina ceramic samples with a MgO content of 0.1 wt%, after sintering at 1700 degrees C for 5 hours, the in-line transmittance at 640 nm (with a sample thickness of 0.65 mm) was measured at 47.15 %, the flexural strength was 408.92 +/- 37.96 MPa, the Vickers hardness was 14.22 +/- 0.28 GPa, and the fracture toughness was 3.36 +/- 0.06 MPa & sdot;m1/2.