Enhanced Properties of 3D Printed Alumina Ceramic Cores via the Introduction of Modified Aramid Fiber

ABSTRACT

Porous ceramic cores are widely used in high‐temperature filtration, catalytic carriers, aerospace, and precision casting due to their lightweight, high specific surface area, and excellent thermal stability. However, achieving a balance between high porosity and mechanical strength remains a key challenge. In this study, modified aramid fiber microspheres (20 µm) were introduced as pore‐forming agents into a photocurable alumina slurry, and the sintering process was optimized to achieve isotropic shrinkage. After systematically evaluating printing orientation, pore‐forming agent content, and sintering temperature, the optimal scheme was determined: horizontal printing with 9% pore‐forming agent, followed by sintering at 1600°C. The resulting alumina ceramic core exhibited high porosity (32.48 ± 0.31%), high flexural strength (20.51 ± 0.93 MPa), and excellent surface accuracy (Ra = 6.46 ± 0.40 µm). Furthermore, finite element simulations clarified the influence of pore structure on mechanical performance. This study achieved an effective balance between porosity and mechanical strength in 3D printed alumina ceramics, providing a new method for fabricating lightweight, thermally stable ceramic cores with tunable pore structures.