Progress in Preparation of Transparent Ceramics by Spontaneous Coagulation Casting
Abstract
Spontaneous coagulation casting (SCC) is a novel in-situ ceramic forming method, involving an anion dispersant which acts as both dispersing and coagulating agent and works well at room temperature in air. Ceramic particles in a slurry prepared by SCC participate in the formation of organic network which is originates from hydrophobic interaction and hydrogen bonding among the dispersant molecular chains, quite different from other gelcasting systems. The ceramic gel formed by SCC is a physical gel and the formed organic network among ceramics particles possesses low density which is conducive to water transportation and stress relaxation during drying.
The research progress in the preparation of transparent ceramics by SCC over the last decade is reviewed in this paper, mainly including powder dispersion and high solid loading slurry preparation, slurry solidification and drying, densification of green bodies, and preparation of large size and high optical quality transparent ceramics. It involves translucent alumina, and hightransmittance transparent alumina ceramics, yttrium oxide, AlON, yttrium aluminum garnet and MgAl2O4 transparent ceramics. For the transparent alumina ceramics, the shear force in the flow of slurries during casting was used to horizontally arrange alumina platelets in the slurry of equiaxed alumina grains, grain orientation occurred through the platelet as templates during sintering. Alumina single-crystal-like structure formed and high transmittance alumina ceramics resulted. For yttria and AlON transparent ceramics, before SCC yttria and AlON powders were respectively treated with organic compounds to ensure them hydrophobic and water resistant because the powders easily react with water which changes the chemical composition of the powders and decreases solid loading of the slurries.
More recently, MgAl2O4 transparent ceramics with a dimension of 470mm×235mm×10 mm was successfully prepared by SCC and vacuum sintering. SCC has become a universal method for preparing transparent ceramics, which is promising in preparing transparent ceramics with complex shapes and high optical quality.
References
YOUNG A C, OMATETE O O, JANNEY M A, et al. Gelcasting of Alumina. Journal of the American Ceramic Society [J]. 1991, 74 (3): 612-618.
MAO X J, SHIMAI S Z, DONG M J, et al. Gelcasting of alumina using epoxy resin as a gelling agent. Journal of the American Ceramic Society [J]. 2007, 90 (3): 986-988.
YANG Y, SHIMAI S, WANG S W. Room-temperature gelcasting of alumina with a water-soluble copolymer. Journal of Materials Research [J]. 2013, 28 (11): 1512-1516.
WANG SW. Progress in research on spontaneous solidification of ceramic slurry based on hydrophobicity [J]. Journal of Inorganic Materials, 2013, 28 (11): 1512-1516.
SUN Y, SHIMAI S Z, PENG X, et al. Gelcasting and vacuum sintering of translucent alumina ceramics with high transparency. Journal of Alloys and Compounds [J]. 2015, 641: 75-79.
SUN Y, SHIMAI S Z, PENG X, et al. Fabrication of transparent Y2O3 ceramics via aqueous gelcasting. Ceramics International [J]. 2014, 40 (6): 8841-8845.
WANG J, ZHANG F, CHEN F, et al. Fabrication of aluminum oxynitride (γ-AlON) transparent ceramics with modified gelcasting. Journal of the American Ceramic Society [J]. 2014, 97 (5): 1353-1355.
QIN X P, ZHOU G H, YANG Y, et al. Gelcasting of transparent YAG ceramics by a new gelling system. Ceramics International [J]. 2014, 40 (8): 12745-12750.
SUN YI Q X, ZHOU GUOHONG, ZHANG HAILONG, et al. Gelcasting and reactive sintering of sheet-like YAG transparent ceramics. Journal of Alloys and Compounds: An Interdisciplinary Journal of Materials Science and Solid-state Chemistry and Physics [J]. 2015, 652: 250-253.
SHAHBAZI H, SHOKROLLAHI H, TATAEI M. Gel-casting of transparent magnesium aluminate spinel ceramics fabricated by spark plasma sintering (SPS). Ceramics International [J]. 2018, 44 (5): 4955-4960.
MARSICO C A, ORLICKI J A, BLAIR V L. Investigation of room‐ temperature super-stabilized suspension casting system mechanism. Journal of the American Ceramic Society [J]. 2020, 103 (3): 1514–1519.
CHEN H, SHIMAI S Z, ZHAO J, et al. Hydrophobic coagulation of alumina slurries. Journal of the American Ceramic Society [J]. 2021, 104 (1): 284-293.
WU X L, ZHAO J, SHIMAI S Z, et al. Re-fluidising the aged gel for high-density alumina green body. Journal of Advanced Ceramics [J]. 2022, 11 (9): 1375-1382.
CHEN H, ZHAO J, SHIMAI S Z, et al. High transmittance and grain-orientated alumina ceramics fabricated by adding fine template particles. Journal of Advanced Ceramics [J]. 2022, 11 (4): 582-588.
CHEN H, SHIMAI S, ZHAO J, et al. Highly oriented α-Al2O3 transparent ceramics shaped by shear force. Journal of the European Ceramic Society [J]. 2021, 41 (6): 3838-3843.
YAO Q, ZHANG L, JIANG Z, et al. Isobam assisted slurry optimization and gelcasting of transparent YAG ceramics. Ceramics International [J]. 2018, 44 (2): 1699-1704.
CHEN L, LUO Y, XIA Y, et al. Densification, microstructure and optical properties of YAG transparent ceramics prepared by dry-pressing and gelcasting. Optical Materials [J]. 2021, 121: 111509.
京公网安备11010802044758号