3D printing of porcelain: finite element simulation of anisotropic sintering

Sintering is a key step that determines the mechanical performances and shape quality of 3D printed ceramics. In this domain, there is an increasing interest in complex thin structures and low fill density shapes. However, these complex structures may suffer from distortions by gravity forces developed on the light structure, friction with supports, shrinkage anisotropy, or thermal gradients. Finite element simulation of the sintering process is then of high importance for predicting the specimens distortions. This paper focuses on the identification of the model parameters in the special case of anisotropic sintering of porcelain with final stage swelling. This study points out the printed specimen high resistance to high temperature shear deformation due to the alignment of the printed rods. A mesoscale simulation has been carried out to explain this mechanism. The resulting model was tested for the sintering of a thin wall cup shape.