Effect of debinding temperature under an argon atmosphere on the microstructure and properties of 3D-printed alumina ceramics

Abstract Debinding at different temperatures under an argon atmosphere, combined with sintering, was used to obtain alumina ceramics fabricated from stereolithography-based 3D printing. The effect of debinding temperature under an argon atmosphere on the microstructure, physical, and mechanical properties were investigated. The results showed that the alumina ceramics had a layered structure, and the interlayer spacing first increased and then decreased with the debinding temperature. Some carbon residue was observed when debinding was performed between 350 and 450 oC, and no residual carbon was observed when the debinding temperature was higher than 500 oC. The shrinkage in the Z direction was much greater than that of the X or Y directions due to layer-by-layer forming mode. There was a slight fluctuation in mechanical properties such as flexural strength (18.9-22.3 MPa), Vickers hardness (110.6-173.7 HV), and nano-indentation hardness (16.9-22.6 GPa). The optimal debinding temperature was 500 oC under an argon atmosphere, which displayed a shrinkage of 2.3% in the X direction, 1.9% in the Y direction, and 3.4% in the Z direction. At this temperature, the flexural strength of the ceramics was 22.3 MPa and the open porosity of the ceramics was 35.6%.