J. Mater. Sci. Technol. ›› 2023, Vol. 157: 71-79.DOI: 10.1016/j.jmst.2022.12.078

• Research Article • Previous Articles     Next Articles

Microstructure and properties of silica-based ceramic cores by laser powder bed fusion combined with vacuum infiltration

Jie Zhanga,b, Jia-Min Wua,b,*, Heng Liua,b, Wen Zhenga,b, Chun-Sheng Yea,b,*, Shi-Feng Wena,b, Chun-Ze Yana,b, Yu-Sheng Shia,b   

  1. aState Key Laboratory of Materials Processing and Die & Mould Technology, School of Materials Science and Engineering, Huazhong University of Science and Technology, Wuhan 430074, China;
    bEngineering Research Center of Ceramic Materials for Additive Manufacturing, Ministry of Education, Wuhan 430074, China
  • Received:2022-10-17 Revised:2022-10-17 Accepted:2022-10-17 Published:2023-09-10 Online:2023-09-07
  • Contact: *State Key Laboratory of Materials Processing and Die & Mould Technology, School of Materials Science and Engineering, Huazhong Uni- versity of Science and Technology, Wuhan 430074, China. E-mail addresses:. jiaminwu@hust.edu.cn (J.-M. Wu), csye@hust.edu.cn (C.-S. Ye)

Abstract: The silica-based ceramic core has attracted much attention in the preparation of hollow blades due to its great leachability. In this paper, the silica-based ceramic cores reinforced with ZrSiO4 were prepared by laser powder bed fusion (LPBF) combined with vacuum infiltration (VI). To enhance the infiltration effect, the pre-sintered bodies with high porosity and hydrophilicity were obtained by pre-sintering at 1100 °C. Results showed that a large number of silica particles infiltrated into the pre-sintered bodies. The infiltrated silica promoted the generation of liquid phase in sintering, thereby promoting the removal of pores and the connection of grains. Nevertheless, the dispersed ZrSiO4 grains prevented the viscous flow of the liquid phase, thereby increasing the porosity. ZrSiO4 grains could hinder the propagation of cracks due to their high strength. When the addition of ZrSiO4 was 10 wt.%, room-temperature flexural strength of silica-based ceramic cores infiltrated with slurry S1 (the mass ratio of silica sol to silica powder was 10:1) reached 17.21 MPa due to the reinforcement of sintering necks. Moreover, high-temperature flexural strength reached 13.90 MPa. Therefore, the pre-sintering process could greatly improve the mechanical properties of silica-based ceramic cores prepared by LPBF-VI technology.

Key words: Silica-based ceramic cores, Laser powder bed fusion, ZrSiO4, Pre-sintering, Vacuum infiltration