Modeling anisotropic sintering for fused deposition modeling of alumina

Additive manufacturing, particularly molten filament deposition, has revolutionized the production of complex parts, offering rapid fabrication from ceramics to metals. Nanoe (R) uses this technology to print intricate ceramic and metal components within minutes to hours. However, challenges arise during the sintering process, including intrinsic anisotropy leading to part deformation and the risk of cracks with rapid heating, especially in porous structures. To address these challenges, our study has developed a sintering simulation framework. The primary objectives include simulating the sintering process of parts printed with Nanoe filaments, characterizing the unique behavior of each filament, and establishing a comprehensive library of material properties for accurate sintering simulation. The framework has been validated through strong agreement between experimental and simulated results, demonstrating its ability to predict anisotropic behavior in alumina parts. The analysis of shrinkage rates, densification kinetics, and mechanistic aspect has provided valuable insights into optimizing sintering processes for improved reliability and precision. In this presentation article, the sintering model identification method is presented for alumina. The method is first tested on pressed powder which is isotropic and then adapted to 3D-printed sample that has an intrinsic anisotropy. Ultimately, our goal is to provide a valuable numerical tool for optimizing the additive manufacturing shapes design.