1. Department of Inorganic Materials, School of Minerals Processing and Bioengineering, Central South University, Changsha 410083, China; 2. Hunan Key Laboratory of Mineral Materials and Application, Central South University, Changsha 410083, China
Abstract：In this study, α-Al2O3 was selected as a mineralizer for the preparation of silica based ceramic cores used in precision casting. Techniques such as X-ray diffractometer, field emission scanning electron microscope, energy dispersive spectroscopy, and the three-point bending testing were employed to investigate the effects of mineralizer amount and silica sol strengthening treatment on the phase composition, microstructures, shrinkage rate, open porosity, density, and bending strength of the ceramic cores. The results indicate that α-Al2O3 exerts a dual effect on the ceramic cores. On one hand, it acts as a reinforcing phase that hinders the viscous flow of fused quartz and enhances the strength of the cores; on the other hand, its excellent high-temperature stability reduces the sintering density of the ceramic cores, leading to decreased shrinkage rates and strength. However, silica sol strengthening treatment effectively seals the pores and promotes sintering of the cores. After silica sol strengthening treatment, cores with w(α-Al2O3)=2% exhibit an increase in room temperature bending strength to 16.6 MPa and high-temperature bending strength to 37.5 MPa, meeting the application standards for ceramic cores in the precision casting industry.
彭勇慧, 周文韬, 寇宝弘, 欧阳静. α-Al2O3及硅溶胶强化处理对氧化硅基陶瓷型芯组织和性能的影响[J]. 粉末冶金材料科学与工程, 2025, 30(2): 115-122.
PENG Yonghui, ZHOU Wentao, KOU Baohong, OUYANG Jing. Effects of α-Al2O3 and silica sol strengthening treatment on the microstructure and performance of silica based ceramic cores. Materials Science and Engineering of Powder Metallurgy, 2025, 30(2): 115-122.
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2025, Vol. 30 
