Effect of Mullite Fiber Content on the Properties of Silica Ceramic Cores Prepared by Selective Laser Sintering Combined with Vacuum Infiltration
Author of the article: LIU Heng1,2, LIU Handi1,2, ZHANG Renzhong1,2, WU Jiamin1,2,3, YAN Chunze1,2, WEN Shifeng1,2, CHENC
Author's Workplace：1. State Key Laboratory of Materials Processing and Die & Mold Technology, School of Materials Science and Engineering, Huazhong University of Science and Technology, Wuhan 430074, China; 2. Engineering Research Center of Ceramic Materials for Additive Manufacturing, Ministry of Education, Wuhan 430074, China; 3. Wenzhou Key Laboratory of Microwave Communication Materials and Devices, Wenzhou Advanced Manufacturing Institute of HUST, Wenzhou 325035, China; 4. State Key Laboratory of Advanced Special Steels, School of Materials Science and Engineering, Shanghai University, Shanghai 200444, China
Key Words：SiO2 ceramic cores; selective laser sintering; vacuum infiltration; mullite fiber contents; mechanical properties.
Abstract：
Silicon dioxide (SiO2
) ceramic cores are essential for manufacturing turbine hollow blades because of their low
thermal expansion coefficient, low sintering temperature, and excellent acid-base leaching resistance. The traditional process
is limited by the use of molds when forming ceramic cores. Some complex structural ceramic cores are even difficult to
manufacture, and the production of high-quality complex structural ceramic cores is challenging. In this study, SiO2
ceramic
cores were prepared via a combination of selective laser sintering (SLS) and vacuum infiltration (VI) techniques. Mullite
fibers were used as the reinforcing phase, the interference of mullite fibers on the sintering process of SiO2
grains and the
delamination phenomenon caused by the accumulation between layers were then analysed, and the influence of the mullite
fiber content on the properties of the SiO2
ceramic core prepared by SLS-VI was clarified. The comprehensive performance
of the ceramic core is the best when the fiber content is 1 wt.%, with a porosity of 31.16%, a flexural strength at room temperature of 15.23 MPa, and a flexural strength at high temperature of 22.91 MPa.
