Preparation of a defect-free alumina cutting tool via additive manufacturing based on stereolithography – Optimization of the drying and debinding processes

A dense defect-free alumina cutting tool was fabricated via stereolithography process. Different drying processes and debinding profiles were then tested and compared to find the optimal way for the preparation of the sintered body. The experimental results showed that using PEG400 as a liquid desiccant results in a lower deformation of the body compared to the natural drying process. Compared with vacuum debinding or air debinding, a two-step debinding process, which consisted of both a vacuum pyrolysis step and the following air debinding, is allowed to control the pyrolysis rate while suppressing the formation of defects in the alumina body. After optimization of the postprocessing, the relative density of the sample as high as 99.3%, and the Vickers hardness ∼17.5 GPa. These properties are similar to the properties of alumina bodies prepared via the conventional shaping method.