Journal of the Chinese Ceramic Society, Volume. 50, Issue 3, 819(2022)

Hydration Damage Mechanism of BaZrO3/Al2O3 Composite Mold and Its Effect on Directionally Solidified TiAl Alloy

XIONG Fuhao1...2,*, CHEN Guangyao1,2,3, DUAN Baohua1,2, MAO Lu1,2, ZHANG Xuexian1,2, ZOU Xingli1,2, and LI Chonghe1,24 |Show fewer author(s)
Author Affiliations
  • 1[in Chinese]
  • 2[in Chinese]
  • 3[in Chinese]
  • 4[in Chinese]
  • show less

    BaZrO3/Al2O3 composite molds were prepared via sintering at 1 600 ℃ for 8 h with BaZrO3 as a surface coating material and Al2O3 as a backup coating material. The phase composition and microstructure of the interfacial bonding layer between the face and back layers before and after hydration were investigated by optical microscopy, X-ray diffraction, and scanning electron microscopy with energy dispersive spectroscopy. The hydration process and damage mechanism of the interfacial bonding layer in the mold were analyzed. The effect of mold damage on the directional solidification of TiAl alloy was also investigated via directional solidification tests. The results show that BaZrO3 and Al2O3 generate BaAl2O4 at BaZrO3/Al2O3 interface during the high-temperature sintering process; and BaAl2O4 generates Ba(AlO(OH)2)2, Ba2Al4(OH)16 and Ba3(Al(OH)6)2 after hydration, leading to the grain volume change to destroy the intergranular bonding force, the generation of cracks in the mold and the failure of the mold. In the directional solidification process, the generated cracks become a channel for melt penetration of TiAl alloy, resulting in a melt leakage from the mold and the appearance of heterogeneous crystals in the directionally solidified TiAl alloy castings.

    Tools

    Get Citation

    Copy Citation Text

    XIONG Fuhao, CHEN Guangyao, DUAN Baohua, MAO Lu, ZHANG Xuexian, ZOU Xingli, LI Chonghe. Hydration Damage Mechanism of BaZrO3/Al2O3 Composite Mold and Its Effect on Directionally Solidified TiAl Alloy[J]. Journal of the Chinese Ceramic Society, 2022, 50(3): 819

    Download Citation

    EndNote(RIS)BibTexPlain Text
    Save article for my favorites
    Paper Information

    Category:

    Received: Jun. 15, 2021

    Accepted: --

    Published Online: Nov. 11, 2022

    The Author Email: Fuhao XIONG (xiongfuhao@shu.edu.cn)

    DOI:10.14062/j.issn.0454-5648.20210485

    Topics