TY - JOUR
T1 - Residual α–Si3N4 in O′ Crystals in CeO2‐Doped O′+β′ SiAlON Ceramics
AU - Xu, Youren
AU - Huang, Chao M.
AU - Kriven, Waltraud M.
AU - Zangvil, Avigdor
PY - 1994/8
Y1 - 1994/8
N2 - The microstructure of a pressureless sintered (1605°C, 90 min) O′+β′ SiAlON ceramic with CeO2 doping has been investigated. It is duplex in nature, consisting of very large, slablike elongated O′ grains (20–30 μm long), and a continuous matrix of small rodlike β′ grains (< 1.0 μm in length). Many α‐Si3N4 inclusions (0.1–0.5 μm in size) were found in the large O′ grains. CeO2‐doping and its high doping level as well as the high Al2O3 concentration were thought to be the main reasons for accelerating the reaction between the α‐Si3N4 and the Si‐Al‐O‐N liquid to precipitate O′–SiAlON. This caused the supergrowth of O′ grains. The rapid growth of O′ crystals isolated the remnant α–Si3N4 from the reacting liquid, resulting in a delay in the α→β‐Si3N4 transformation. The large O′ grains and the α‐Si3N4 inclusions have a pronounced effect on the strength degradation of O′+β′ ceramics.
AB - The microstructure of a pressureless sintered (1605°C, 90 min) O′+β′ SiAlON ceramic with CeO2 doping has been investigated. It is duplex in nature, consisting of very large, slablike elongated O′ grains (20–30 μm long), and a continuous matrix of small rodlike β′ grains (< 1.0 μm in length). Many α‐Si3N4 inclusions (0.1–0.5 μm in size) were found in the large O′ grains. CeO2‐doping and its high doping level as well as the high Al2O3 concentration were thought to be the main reasons for accelerating the reaction between the α‐Si3N4 and the Si‐Al‐O‐N liquid to precipitate O′–SiAlON. This caused the supergrowth of O′ grains. The rapid growth of O′ crystals isolated the remnant α–Si3N4 from the reacting liquid, resulting in a delay in the α→β‐Si3N4 transformation. The large O′ grains and the α‐Si3N4 inclusions have a pronounced effect on the strength degradation of O′+β′ ceramics.
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U2 - 10.1111/j.1151-2916.1994.tb07123.x
DO - 10.1111/j.1151-2916.1994.tb07123.x
M3 - Article
AN - SCOPUS:0028493418
SN - 0002-7820
VL - 77
SP - 2213
EP - 2216
JO - Journal of the American Ceramic Society
JF - Journal of the American Ceramic Society
IS - 8
ER -