Influence of Sintering Temperature on Microstructure and Mechanical Properties of Al₂O₃ Ceramic via 3D Stereolithography

In this work, aluminum oxide (Al₂O₃) ceramic samples were fabricated by 3D stereolithography printing. Printing process was followed by debinding and sintering. In addition, the effect of sintering temperature on microstructure and properties was investigated. Flexure strength was observed to increase with increasing sintering temperature due to fewer pores, fewer defects and stronger grain boundary bonding of samples at higher sintering temperatures. Maximum flexure strength of 138.5 MPa was obtained when sintering temperature was 150 °C. Furthermore, the shrinkage along length direction decreased with the decreasing sintering temperature until reaching minimum value of 1.02% after sintering at 1200 °C. After sintering at 1280 °C, flexure strength was 24.0 MPa and the shrinkage along length direction was 2.1%, which meets demands of ceramic core.