Regulation of residual stress in stereolithography printing of ZrO2 ceramics

Stereolithography (SL) is an important additive manufacturing method for preparing ceramic parts. To reduce the warpage, deformation, cracking, and other defects caused by residual stress existing in SL 3D-printed parts, residual stress needs to be adjusted. In this work, two methods to control residual stress developed in SL 3D-printed parts were studied, which consisted of optimizing the degreasing–sintering process and blending material components. A major technique is to adjust the surface residual stress of SL 3D-printed zirconia (ZrO2) ceramic samples by optimizing the degreasing–sintering process. Sintering temperature, holding time, and heating rate have a great influence on the surface residual tensile stress. The second method to adjust the residual stress consists of adding new components. A carbon material, i.e., graphene oxide (GO), was added to ZrO2 ceramic material. The results illustrate that GO significantly reduces the residual stress in SL 3D-printed parts.