Influence of Vacuum Debinding Temperature on Microstructure and Mechanical Properties of Three-Dimensional-Printed Alumina via Stereolithography

Herein, the influence of vacuum debinding temperature on microstructure and mechanical properties of three-dimensional-printed alumina is systematically investigated by employing a variety of characterization techniques. The results reveal that the debinding temperature >400°C resulted in negligible weight loss. Moreover, the crystallite size of the sintered alumina decreased with increasing debinding temperature. The lower debinding temperature of 300-350°C did not remove the photosensitive resin, which resulted in a loose lamellar structure. However, the higher debinding temperature (450-600°C) resulted in several irregular small-sized particles. Moreover, the size of alumina particles increased after the sintering process. The Raman analysis revealed that the debinded samples contain C, Al, and O; however, the C has not been detected after sintering. In general, the physical properties, such as shrinkage, open porosity, and relative density, exhibited a close relationship with the flexural strength, which is influenced by the debinding temperature. Based on the physical properties and processing requirements, the optimal vacuum debinding temperature should be in the range of 400-500°C.